facility that installs
                                                                                catalytic cracking feed
                                                                                hydrotreating and
                                                                                receives an extended
                                                                                compliance date under
                                                                                Sec.   63.1563(c).
Sec.   63.6(i)(15)................  [Reserved]................  Not applicable.......  .........................
Sec.   63.6(i)(16)................  ..........................  Yes..................  .........................
Sec.   63.6(j)....................  Presidential Compliance     Yes..................  .........................
                                     Exemption.
Sec.   63.7(a)(1).................  Performance Test            Yes..................  Except that this subpart
                                     Requirements                                       specifies the applicable
                                     Applicability.                                     test and demonstration
                                                                                procedures.
Sec.   63.7(a)(2).................  Performance Test Dates....  Yes..................  Except test results must
                                                                                be submitted in the
                                                                                Notification of
                                                                                Compliance Status report
                                                                                due 150 days after the
                                                                                compliance date.
Sec.   63.7(a)(3).................  Section 114 Authority.....  Yes..................  .........................
Sec.   63.7(a)(4).................  Force Majeure.............  Yes..................  .........................
Sec.   63.7(b)....................  Notifications.............  Yes..................  Except that this subpart
                                                                                specifies notification
                                                                                at least 30 days prior
                                                                                to the scheduled test
                                                                                date rather than 60
                                                                                days.
Sec.   63.7(c)....................  Quality Assurance Program/  Yes..................  Except that when this
                                     Site-Specific Test Plan.                           subpart specifies to use
                                                                                40 CFR part 60, appendix
                                                                                F, out of control
                                                                                periods are to be
                                                                                defined as specified in
                                                                                part 60, appendix F.
Sec.   63.7(d)....................  Performance Test            Yes..................  .........................
                                     Facilities.
Sec.   63.7(e)(1).................  Performance Testing.......  No...................  See Sec.   63.1571(b)(1).
Sec.   63.7(e)(2)-(4).............  Conduct of Tests..........  Yes..................  .........................
Sec.   63.7(f)....................  Alternative Test Method...  Yes..................  .........................
Sec.   63.7(g)....................  Data Analysis,              Yes..................  Except performance test
                                     Recordkeeping, Reporting.                          reports must be
                                                                                submitted with
                                                                                notification of
                                                                                compliance status due
                                                                                150 days after the
                                                                                compliance date, and
                                                                                Sec.   63.7(g)(2) is
                                                                                reserved and does not
                                                                                apply.
Sec.   63.7(h)....................  Waiver of Tests...........  Yes..................  .........................
Sec.   63.8(a)(1).................  Monitoring Requirements-    Yes..................  .........................
                                     Applicability.
Sec.   63.8(a)(2).................  Performance Specifications  Yes..................  .........................
Sec.   63.8(a)(3).................  [Reserved]................  Not applicable.......  .........................
Sec.   63.8(a)(4).................  Monitoring with Flares....  Yes..................  Except that for a flare
                                                                                complying with Sec.
                                                                                63.670, the cross-
                                                                                reference to Sec.
                                                                                63.11 in this paragraph
                                                                                does not include Sec.
                                                                                63.11(b).
Sec.   63.8(b)(1).................  Conduct of Monitoring.....  Yes..................  .........................
Sec.   63.8(b)(2)-(3).............  Multiple Effluents and      Yes..................  This subpart specifies
                                     Multiple Monitoring                                the required monitoring
                                     Systems.                                           locations.
Sec.   63.8(c)(1).................  Monitoring System           Yes..................  .........................
                                     Operation and Maintenance.
Sec.   63.8(c)(1)(i)..............  General Duty to Minimize    No...................  See Sec.   63.1570(c).
                                     Emissions and CMS
                                     Operation.
Sec.   63.8(c)(1)(ii).............  Keep Necessary Parts for    Yes..................  .........................
                                     CMS.
Sec.   63.8(c)(1)(iii)............  Requirement to Develop SSM  No...................  .........................
                                     Plan for CMS.

Sec.   63.8(c)(2)-(3).............  Monitoring System           Yes..................  Except that this subpart
                                     Installation.                                      specifies that for
                                                                                continuous parameter
                                                                                monitoring systems,
                                                                                operational status
                                                                                verification includes
                                                                                completion of
                                                                                manufacturer written
                                                                                specifications or
                                                                                installation, operation,
                                                                                and calibration of the
                                                                                system or other written
                                                                                procedures that provide
                                                                                adequate assurance that
                                                                                the equipment will
                                                                                monitor accurately.
Sec.   63.8(c)(4).................  Continuous Monitoring       Yes..................  .........................
                                     System Requirements.
Sec.   63.8(c)(5).................  COMS Minimum Procedures...  Yes..................  .........................
Sec.   63.8(c)(6).................  CMS Requirements..........  Yes..................  .........................
Sec.   63.8(c)(7)-(8).............  CMS Requirements..........  Yes..................  .........................
Sec.   63.8(d)(1)-(2).............  Quality Control Program     Yes..................  .........................
                                     for CMS.
Sec.   63.8(d)(3).................  Written Procedures for CMS  No...................  .........................
Sec.   63.8(e)....................  CMS Performance Evaluation  Yes..................  Except that results are
                                                                                to be submitted as part
                                                                                of the Notification
                                                                                Compliance Status due
                                                                                150 days after the
                                                                                compliance date.
Sec.   63.8(f)(1)-(5).............  Alternative Monitoring      Yes..................  Except that this subpart
                                     Methods.                                           specifies procedures for
                                                                                requesting alternative
                                                                                monitoring systems and
                                                                                alternative parameters.
Sec.   63.8(f)(6).................  Alternative to Relative     Yes..................  Applicable to continuous
                                     Accuracy Test.                                     emission monitoring
                                                                                systems if performance
                                                                                specification requires a
                                                                                relative accuracy test
                                                                                audit.
Sec.   63.8(g)(1)-(4).............  Reduction of Monitoring     Yes..................  Applies to continuous
                                     Data.                                              opacity monitoring
                                                                                system or continuous
                                                                                emission monitoring
                                                                                system.
Sec.   63.8(g)(5).................  Data Reduction............  No...................  This subpart specifies
                                                                                requirements.
Sec.   63.9(a)....................  Notification Requirements-- Yes..................  Duplicate Notification of
                                     Applicability.                                     Compliance Status report
                                                                                to the Regional
                                                                                Administrator may be
                                                                                required.
Sec.   63.9(b)(1)-(2).............  Initial Notifications.....  Yes..................  Except that notification
                                                                                of construction or
                                                                                reconstruction is to be
                                                                                submitted as soon as
                                                                                practicable before
                                                                                startup but no later
                                                                                than 30 days after the
                                                                                effective date if
                                                                                construction or
                                                                                reconstruction had
                                                                                commenced but startup
                                                                                had not occurred before
                                                                                the effective date.
Sec.   63.9(b)(3).................  [Reserved]................  Not applicable.......  .........................
Sec.   63.9(b)(4)-(5).............  Initial Notification        Yes..................  Except Sec.
                                     Information.                                       63.9(b)(4)(ii)-(iv),
                                                                                which are reserved and
                                                                                do not apply.
Sec.   63.9(c)....................  Request for Extension of    Yes..................  .........................
                                     Compliance.
Sec.   63.9(d)....................  New Source Notification     Yes..................  .........................
                                     for Special Compliance
                                     Requirements.
Sec.   63.9(e)....................  Notification of             Yes..................  Except that notification
                                     Performance Test.                                  is required at least 30
                                                                                days before test.
Sec.   63.9(f)....................  Notification of VE/Opacity  Yes..................  .........................
                                     Test.
Sec.   63.9(g)....................  Additional Notification     Yes..................  .........................
                                     Requirements for Sources
                                     with Continuous
                                     Monitoring Systems.
Sec.   63.9(h)....................  Notification of Compliance  Yes..................  Except that this subpart
                                     Status.                                            specifies the
                                                                                notification is due no
                                                                                later than 150 days
                                                                                after compliance date,
                                                                                and except that the
                                                                                reference to Sec.
                                                                                63.5(d)(1)(ii)(H) in
                                                                                Sec.   63.9(h)(5) does
                                                                                not apply.
Sec.   63.9(i)....................  Adjustment of Deadlines...  Yes..................  .........................
Sec.   63.9(j)....................  Change in Previous          Yes..................  .........................
                                     Information.
63.10(a)..........................  Recordkeeping and           Yes..................  .........................
                                     Reporting Applicability.
Sec.   63.10(b)(1)................  General Recordkeeping       Yes..................  .........................
                                     Requirements.

Sec.   63.10(b)(2)(i).............  Recordkeeping of            No...................  .........................
                                     Occurrence and Duration
                                     of Startups and Shutdowns.
Sec.   63.10(b)(2)(ii)............  Recordkeeping of            No...................  See Sec.   63.1576(a)(2)
                                     Malfunctions.                                      for recordkeeping of (1)
                                                                                date, time and duration;
                                                                                (2) listing of affected
                                                                                source or equipment, and
                                                                                an estimate of the
                                                                                volume of each regulated
                                                                                pollutant emitted over
                                                                                the standard; and (3)
                                                                                actions taken to
                                                                                minimize emissions and
                                                                                correct the failure.
Sec.   63.10(b)(2)(iii)...........  Maintenance Records.......  Yes..................  .........................
Sec.   63.10(b)(2)(iv)-(v)........  Actions Taken to Minimize   No...................  .........................
                                     Emissions During SSM.
Sec.   63.10(b)(2)(vi)............  Recordkeeping for CMS       Yes..................  .........................
                                     Malfunctions.
Sec.   63.10(b)(2)(vii)-(xiv).....  Other CMS Requirements....  Yes..................  .........................
Sec.   63.10(b)(3)................  Recordkeeping for           Yes..................  .........................
                                     Applicability
                                     Determinations..
Sec.   63.10(c)(1)-(6)............  Additional Records for      Yes..................  Except Sec.   63.10(c)(2)-
                                     Continuous Monitoring                              (4), which are Reserved
                                     Systems.                                           and do not apply.
Sec.   63.10(c)(7)-(8)............  Additional Recordkeeping    Yes..................  .........................
                                     Requirements for CMS--
                                     Identifying Exceedances
                                     and Excess Emissions.
Sec.   63.10(c)(9)................  [Reserved]................  Not applicable.......  .........................
Sec.   63.10(c)(10)...............  Recording Nature and Cause  No...................  See Sec.   63.1576(a)(2)
                                     of Malfunctions.                                   for malfunctions
                                                                                recordkeeping
                                                                                requirements.
Sec.   63.10(c)(11)...............  Recording Corrective        No...................  See Sec.   63.1576(a)(2)
                                     Actions.                                           for malfunctions
                                                                                recordkeeping
                                                                                requirements.
Sec.   63.10(c)(12)-(14)..........  Additional CMS              Yes..................  .........................
                                     Recordkeeping
                                     Requirements.
Sec.   63.10(c)(15)...............  Use of SSM Plan...........  No...................  .........................
Sec.   63.10(d)(1)................  General Reporting           Yes..................  .........................
                                     Requirements.
Sec.   63.10(d)(2)................  Performance Test Results..  No...................  This subpart requires
                                                                                performance test results
                                                                                to be reported as part
                                                                                of the Notification of
                                                                                Compliance Status due
                                                                                150 days after the
                                                                                compliance date.
Sec.   63.10(d)(3)................  Opacity or VE Observations  Yes..................  .........................
Sec.   63.10(d)(4)................  Progress Reports..........  Yes..................  .........................
Sec.   63.10(d)(5)................  SSM Reports...............  No...................  See Sec.   63.1575(d) for
                                                                                CPMS malfunction
                                                                                reporting and Sec.
                                                                                63.1575(e) for COMS and
                                                                                CEMS malfunction
                                                                                reporting.
Sec.   63.10(e)(1)-(2)............  Additional CMS Reports....  Yes..................  Except that reports of
                                                                                performance evaluations
                                                                                must be submitted in
                                                                                Notification of
                                                                                Compliance Status.
Sec.   63.10(e)(3)................  Excess Emissions/CMS        No...................  This subpart specifies
                                     Performance Reports.                               the applicable
                                                                                requirements.
Sec.   63.10(e)(4)................  COMS Data Reports.........  Yes..................  .........................
Sec.   63.10(f)...................  Recordkeeping/Reporting     Yes..................  .........................
                                     Waiver.
Sec.   63.11(a)...................  Control Device and Work     Yes..................  .........................
                                     Practice Requirements
                                     Applicability.
Sec.   63.11(b)...................  Flares....................  Yes..................  Except that flares
                                                                                complying with Sec.
                                                                                63.670 are not subject
                                                                                to the requirements of
                                                                                Sec.   63.11(b).
Sec.   63.11(c)-(e)...............  Alternative Work Practice   Yes..................  .........................
                                     for Monitoring Equipment
                                     for Leaks.
Sec.   63.12......................  State Authority and         Yes..................  .........................
                                     Delegations.
Sec.   63.13......................  Addresses.................  Yes..................  .........................
Sec.   63.14......................  Incorporation by Reference  Yes..................  .........................
Sec.   63.15......................  Availability of             Yes..................  .........................
                                     Information and
                                     Confidentiality.
Sec.   63.16......................  Performance Track           Yes..................  .........................
                                     Provisions.
----------------------------------------------------------------------------------------------------------------

0
88. Appendix A to subpart UUU of part 63 is amended by revising the
first sentence of section 2.1 and section 7.1.3 to read as follows:

Appendix A to Subpart UUU of Part 63--Determination of Metal
Concentration on Catalyst Particles (Instrumental Analyzer Procedure)

* * * * *
    2.1 A representative sample of catalyst particles is collected,
prepared, and analyzed for analyte concentration using either energy
or wavelength dispersive X-ray fluorescent (XRF) spectrometry
instrumental analyzers. * * *
* * * * *
    7.1.3 Low-Range Calibration Standard. Concentration equivalent
to 1 to 20 percent of the span. The concentration of the low-range
calibration standard should be selected so that it is less than
either one-fourth of the applicable concentration limit or of the
lowest concentration anticipated in the catalyst samples.
* * * * *

0
89. Appendix A to part 63 is amended by adding Method 325A and Method
325B in numerical order to read as follows:

Appendix A to Part 63--Test Methods Pollutant Measurement Methods From
Various Waste Media

* * * * *
    Method 325A--Volatile Organic Compounds from Fugitive and Area
Sources:

Sampler Deployment and VOC Sample Collection

1.0 Scope and Application

    1.1 This method describes collection of volatile organic
compounds (VOCs) at or inside a facility property boundary or from
fugitive and area emission sources using passive (diffusive) tube
samplers (PS). The concentration of airborne VOCs at or near these
potential fugitive- or area-emission sources may be determined using
this method in combination with Method 325B. Companion Method 325B
(Sampler Preparation and Analysis) describes preparation of sampling
tubes, shipment and storage of exposed sampling tubes, and analysis
of sampling tubes collected using either this passive sampling
procedure or alternative active (pumped) sampling methods.
    1.2 This method may be used to determine the average
concentration of the select VOCs using the corresponding uptake
rates listed in Method 325B, Table 12.1. Additional compounds or
alternative sorbents must be evaluated as described in Addendum A of
Method 325B or by one of the following national/international
standard methods: ISO 16017-2:2003(E), ASTM D6196-03 (Reapproved
2009), or BS EN 14662-4:2005 (all incorporated by reference--see
Sec.  63.14), or reported in the peer-reviewed open literature.
    1.3 Methods 325A and 325B are valid for the measurement of
benzene. Supporting literature (References 1-8) indicates that
benzene can be measured by flame ionization detection or mass
spectrometry over a concentration range of approximately 0.5
micrograms per cubic meter ([micro]g/m3) to at least 500
[micro]g/m\3\ when industry standard (3.5 inch long x 0.25 inch
outside diameter (o.d.) x 5 mm inner diameter (i.d.)) inert-coated
stainless steel sorbent tubes packed with CarbographTM 1
TD, CarbopackTM B, or CarbopackTM X or
equivalent are used and when samples are accumulated over a period
of 14 days.
    1.4 This method may be applied to screening average airborne VOC
concentrations at facility property boundaries or monitoring
perimeters over an extended period of time using multiple sampling
periods (e.g., 26 x 14-day sampling periods). The duration of each
sampling period is normally 14 days.
    1.5 This method requires the collection of local meteorological
data (wind speed and direction, temperature, and barometric
pressure). Although local meteorology is a component of this method,
non-regulatory applications of this method may use regional
meteorological data. Such applications risk that the results may not
identify the precise source of the emissions.

2.0 Summary of the Method

2.1 Principle of the Method

    The diffusive passive sampler collects VOC from air for a
measured time period at a rate that is proportional to the
concentration of vapor in the air at that location.
    2.1.1 This method describes the deployment of prepared passive
samplers, including determination of the number of passive samplers
needed for each survey and placement of samplers along or inside the
facility property boundary depending on the size and shape of the
site or linear length of the boundary.
    2.1.2 The rate of sampling is specific to each compound and
depends on the diffusion constants of that VOC and the sampler
dimensions/characteristics as determined by prior calibration in a
standard atmosphere (Reference 1).
    2.1.3 The gaseous VOC target compounds migrate through a
constant diffusion barrier (e.g., an air gap of fixed dimensions) at
the sampling end of the diffusion sampling tube and adsorb onto the
sorbent.
    2.1.4 Heat and a flow of inert carrier gas are then used to
extract (desorb) the retained VOCs back from the sampling end of the
tube and transport/transfer them to a gas chromatograph (GC)
equipped with a chromatographic column to separate the VOCs and a
detector to determine the quantity of target VOCs.
    2.1.5 Gaseous or liquid calibration standards loaded onto the
sampling ends of clean sorbent tubes must be used to calibrate the
analytical equipment.
    2.1.6 This method requires the use of field blanks to ensure
sample integrity associated with shipment, collection, and storage
of the passive samples. It also requires the use of field duplicates
to validate the sampling process.
    2.1.7 At the end of each sampling period, the passive samples
are collected, sealed, and shipped to a laboratory for analysis of
target VOCs by thermal desorption gas chromatography, as described
in Method 325B.

2.2 Application of Diffusive Sampling

    2.2.1 This method requires deployment of passive sampling tubes
on a monitoring perimeter encompassing all known emission sources at
a facility and collection of local meteorological data. It may be
used to determine average concentration of VOC at a facility's
``fenceline'' using time integrated passive sampling (Reference 2).
    2.2.2 Collecting samples and meteorological data at
progressively higher frequencies may be employed to resolve shorter
term concentration fluctuations and wind conditions that could
introduce interfering emissions from other sources.
    2.2.3 This passive sampling method provides a low cost approach
to screening of fugitive or area emissions compared to active
sampling methods that are based on pumped sorbent tubes or time
weighted average canister sampling.
    <IP_ADDRESS> Additional passive sampling tubes may be deployed at
different distances from the facility property boundary or from the
geometric center of the fugitive emission source.
    <IP_ADDRESS> Additional meteorological measurements may also be
collected as needed to perform preliminary gradient-based assessment
of the extent of the pollution plume at ground level and the effect
of ``background'' sources contributing to airborne VOC
concentrations at the location.
    2.2.4 Time-resolved concentration measurements coupled with
time-resolved meteorological monitoring may be used to generate data
needed for source apportionment procedures and mass flux
calculations.

3.0 Definitions

    (See also Section 3.0 of Method 325B.)
    3.1 Fenceline means the property boundary of a facility or
internal monitoring perimeter established in accordance with the
requirements in Section 8.2 of this method.
    3.2 Passive sampler (PS) means a specific type of sorbent tube
(defined in this method) that has a fixed dimension air (diffusion)
gap at the sampling end and is sealed at the other end.
    3.3 Passive sampling refers to the activity of quantitatively
collecting VOC on sorbent tubes using the process of diffusion.
    3.4 PSi is the annual average for all PS concentration results
from location i.
    3.5 PSi3 is the set of annual average concentration results for
PSi and two sorbent tubes nearest to the PS location i.
    3.6 PSip is the concentration from the sorbent tube at location
i for the test period or episode p.
    3.7 Sampling period is the length of time each passive sampler
is exposed during field monitoring. The sampling period for this
method is 14 days.
    3.8 Sorbent tube (Also referred to as tube, PS tube, adsorbent
tube, and sampling tube) is an inert coated stainless steel tube.
Standard PS tube dimensions for this method

are 3.5-inch (89 mm) long x 0.25-inch (6.4 mm) o.d. with an i.d. of
5 mm, a cross-sectional area of 19.6 mm2 and an air gap
of 15 mm. The central portion of the tube is packed with solid
adsorbent material contained between 2 x 100-mesh stainless steel
gauzes and terminated with a diffusion cap at the sampling end of
the tube. These axial passive samplers are installed under a
protective hood during field deployment.

    Note:  Glass and glass- (or fused silica-) lined stainless steel
sorbent tubes (typically 4 mm i.d.) are also available in various
lengths to suit different makes of thermal desorption equipment, but
these are rarely used for passive sampling because it is more
difficult to adequately define the diffusive air gap in glass or
glass-line tubing. Such tubes are not recommended for this method.

4.0 Sampling Interferences

4.1 General Interferences

    Passive tube samplers should be sited at a distance beyond the
influence of possible obstructions such as trees, walls, or
buildings at the monitoring site. Complex topography and physical
site obstructions, such as bodies of water, hills, buildings, and
other structures that may prevent access to a planned PS location
must be taken into consideration. You must document and report
siting interference with the results of this method.

4.2 Background Interference

    Nearby or upwind sources of target emissions outside the
facility being tested can contribute to background concentrations.
Moreover, because passive samplers measure continuously, changes in
wind direction can cause variation in the level of background
concentrations from interfering sources during the monitoring
period. This is why local meteorological information, particularly
wind direction and speed, is required to be collected throughout the
monitoring period. Interfering sources can include neighboring
industrial facilities, transportation facilities, fueling
operations, combustion sources, short-term transient sources,
residential sources, and nearby highways or roads. As PS data are
evaluated, the location of potential interferences with respect to
PS locations and local wind conditions should be considered,
especially when high PS concentration values are observed.

4.3 Tube Handling

    You must protect the PS tubes from gross external contamination
during field sampling. Analytical thermal desorption equipment used
to analyze PS tubes must desorb organic compounds from the interior
of PS tubes and exclude contamination from external sampler surfaces
in the analytical/sample flow path. If the analytical equipment does
not comply with this requirement, you must wear clean, white, cotton
or powder-free nitrile gloves to handle sampling tubes to prevent
contamination of the external sampler surfaces. Sampling tubes must
be capped with two-piece, brass, 0.25 inch, long-term storage caps
fitted with combined polytetrafluoroethylene ferrules (see Section
6.1 and Method 325B) to prevent ingress of airborne contaminants
outside the sampling period. When not being used for field
monitoring, the capped tubes must be stored in a clean, air-tight,
shipping container to prevent the collection of VOCs (see Section
6.4.2 of Method 325B).

4.4 Local Weather Conditions and Airborne Particulates

    Although air speeds are a constraint for many forms of passive
samplers, axial tube PS devices have such a slow inherent uptake
rate that they are largely immune to these effects (References 4,5).
Passive samplers must nevertheless be deployed under non-emitting
weatherproof hoods to moderate the effect of local weather
conditions such as solar heating and rain. The cover must not impede
the ingress of ambient air. Sampling tubes should also be orientated
vertically and pointing downwards, to minimize accumulation of
particulates.

4.5 Temperature

    The normal working range for field sampling for sorbent packing
is 0-40 [deg]C (References 6,7). Note that most published passive
uptake rate data for sorbent tubes is quoted at 20 [deg]C. Note also
that, as a rough guide, an increase in temperature of 10 [deg]C will
reduce the collection capacity for a given analyte on a given
sorbent packing by a factor of 2, but the uptake rate will not
change significantly (Reference 4).

5.0 Safety

    This method does not purport to include all safety issues or
procedures needed when deploying or collecting passive sampling
tubes. Precautions typical of field air sampling projects are
required. Tripping, falling, electrical, and weather safety
considerations must all be included in plans to deploy and collect
passive sampling tubes.

6.0 Sampling Equipment and Supplies, and Pre-Deployment Planning

    This section describes the equipment and supplies needed to
deploy passive sampling monitoring equipment at a facility property
boundary. Details of the passive sampling tubes themselves and
equipment required for subsequent analysis are described in Method
325B.

6.1 Passive Sampling Tubes

    The industry standard PS tubes used in this method must meet the
specific configuration and preparation requirements described in
Section 3.0 of this method and Section 6.1 of Method 325B.

    Note:  The use of PS tubes packed with various sorbent materials
for monitoring a wide variety of organic compounds in ambient air
has been documented in the literature (References 4-10). Other
sorbents may be used in standard passive sampling tubes for
monitoring additional target compound(s) once their uptake rate and
performance has been demonstrated following procedures in Addendum A
to Method 325B. Guidance on sorbent selection can also be obtained
from relevant national and international standard methods such as
ASTM D6196-03 (Reapproved 2009) (Reference 14) and ISO 16017-
2:2003(E) (Reference 13) (both incorporated by reference--see Sec.
63.14).

6.2 Passive or Diffusive Sampling Cap

    One diffusive sampling cap is required per PS tube. The cap fits
onto the sampling end of the tube during air monitoring. The other
end of the tube remains sealed with the long-term storage cap. Each
diffusive sampling cap is fitted with a stainless steel gauze, which
defines the outer limit of the diffusion air gap.

6.3 Sorbent Tube Protection Cover

    A simple weatherproof hood, suitable for protecting passive
sampling tubes from the worst of the weather (see Section 4.4)
consists of an inverted cone/funnel constructed of an inert, non-
outgassing material that fits over the diffusive tube, with the open
(sampling) end of the tube projecting just below the cone opening.
An example is shown in Figure 6.1 (Adapted from Reference 13).

[GRAPHIC] [TIFF OMITTED] TR01DE15.025

6.4 Thermal Desorption Apparatus

     If the analytical thermal desorber that will subsequently be
used to analyze the passive sampling tubes does not meet the
requirement to exclude outer surface contaminants from the sample
flow path (see Section 6.6 of Method 325B), then clean, white,
cotton or powder-free nitrile gloves must be used for handling the
passive sampling tubes during field deployment.

6.5 Sorbent Selection

    Sorbent tube configurations, sorbents or other VOC not listed in
this method must be evaluated according to Method 325B, Addendum A
or ISO 16017-2:2003(E) (Reference 13) (incorporated by reference--
see Sec.  63.14). The supporting evaluation and verification data
described in Method 325B, Addendum A for configurations or compounds
different from the ones described in this method must meet the
performance requirements of Method 325A/B and must be submitted with
the test plan for your measurement program.

7.0 Reagents and Standards

    No reagents or standards are needed for the field deployment and
collection of passive sampling tubes. Specifications for sorbents,
gas and liquid phase standards, preloaded standard tubes, and
carrier gases are covered in Section 7 of Method 325B.

8.0 Sample Deployment, Recovery, and Storage

    Pre-deployment and planning steps are required before field
deployment of passive sampling tubes. These activities include but
are not limited to conducting a site visit, determining suitable and
required monitoring locations, and determining the monitoring
frequency to be used.

8.1 Conducting the Site Visit

    8.1.1 Determine the size and shape of the facility footprint in
order to determine the required number of monitoring locations.
    8.1.2 Identify obstacles or obstructions (buildings, roads,
fences), hills and other terrain issues (e.g., bodies of water or
swamp land) that could interfere with air parcel flow to the sampler
or that prevent reasonable access to the location. You may use the
general guidance in Section 4.1 of this method during the site visit
to identify sampling locations. You must evaluate the placement of
each passive sampler to determine if the conditions in this section
are met.
    8.1.3 Identify to the extent possible and record potential off-
site source interferences (e.g., neighboring industrial facilities,
transportation facilities, fueling operations, combustion sources,
short-term transient sources, residential sources, nearby highways).
    8.1.4 Identify the closest available meteorological station.
Identify potential locations for one or more on-site or near-site
meteorological station(s) following the guidance in EPA-454/B-08-002
(Reference 11) (incorporated by reference--see Sec.  63.14).

8.2 Determining Sampling Locations (References 2, 3)

    8.2.1 The number and placement of the passive samplers depends
on the size, the shape of the facility footprint or the linear
distance around the facility, and the proximity of emission sources
near the property boundaries. Aerial photographs or site maps may be
used to determine the size (acreage) and shape of the facility or
the length of the monitoring perimeter. Place passive samplers on an
internal monitoring perimeter on or inside the facility boundary
encompassing all emission sources at the facility at different
angles circling the geometric center of the facility or at different
distances based on the monitoring perimeter length of the facility.

    Note: In some instances, permanent air monitoring stations may
already be located in close proximity to the facility. These
stations may be operated and maintained by the site, or local or
state regulatory agencies. If access to the station is possible, a
PS may be deployed adjacent to other air monitoring instrumentation.
A comparison of the pollutant concentrations measured with the PS to
concentrations measured by site instrumentation may be used as an
optional data quality indicator to assess the accuracy of PS
results.

    <IP_ADDRESS> The monitoring perimeter may be located between the
property boundary and any potential emission source near the
property boundary, as long as the distance from the source to the
monitoring perimeter is at least 50 meters (162 feet). If a
potential emissions source is within 50 meters (162 feet) of the
property boundary, the property boundary shall be used as the
monitoring perimeter near that source.
    <IP_ADDRESS> Samplers need only be placed around the monitoring
perimeter and not along internal roads or other right of ways that
may bisect the facility.
    <IP_ADDRESS> Extra samplers must be placed near known sources of VOCs
if the potential emission source is within 50 meters (162 feet) of
the boundary and the source location is between two monitors.
Measure the distance (x) between the two monitors and place another
monitor halfway between (x/2) the two monitors. For example, in
Figure 8.1, the facility added three additional monitors (i.e.,
light shaded sampler locations) and in Figure 8.2, the facility
added two additional monitors to provide sufficient coverage of all
area sources.
BILLING CODE 6560-50-P

[GRAPHIC] [TIFF OMITTED] TR01DE15.026

    8.2.2 Option 1 for Determining Sampling Locations.
    <IP_ADDRESS> For facilities with a regular (circular, triangular,
rectangular, or square) shape, determine the geographic center of
the facility.

    <IP_ADDRESS>.1 For facilities with an area of less than or equal to
750 acres, measure angles of 30 degrees from the center point for a
total of twelve 30 degree measurements evenly spaced (1
degree).
    <IP_ADDRESS>.2 For facilities covering an area greater than 750 acres
but less than or equal to 1,500 acres, measure angles of 20 degrees
from the center point for a total of eighteen 20 degree measurements
evenly spaced (1 degree). Figure 8.1 shows the monitor
placement around the property boundary of a facility with an area
between 750 and 1,500 acres. Monitor placements are represented with
black dots along the property boundary.
    <IP_ADDRESS>.3 For facilities covering an area greater than 1,500
acres, measure angles of 15 degrees from the center point for a
total of twenty-four 15 degree measurements evenly spaced (1 degree).
    <IP_ADDRESS>.4 Locate each sampling point where the measured angle
intersects the outer monitoring perimeter.
    <IP_ADDRESS> For irregularly shaped facilities, divide the area into
a set of connecting subarea circles, triangles or rectangles to
determine sampling locations. The subareas must be defined such that
a circle can reasonably encompass the subarea. Then determine the
geometric center point of each of the subareas.
    <IP_ADDRESS>.1 If a subarea is less than or equal to 750 acres (e.g.,
Figure 8.3), measure angles of 30 degrees from the center point for
a total of twelve 30 degree measurements (1 degree).
[GRAPHIC] [TIFF OMITTED] TR01DE15.027

    <IP_ADDRESS>.2 If a subarea is greater than 750 acres but less than
or equal to 1,500 acres (e.g., Figure 8.4), measure angles of 20
degrees from the center point for a total of eighteen 20 degree
measurements (1 degree).
    <IP_ADDRESS>.3 If a subarea is greater than 1,500 acres, measure
angles of 15 degrees from the center for a total of twenty-four 15
degree measurements (1 degree).
    <IP_ADDRESS>.4 Locate each sampling point where the measured angle
intersects the outer monitoring perimeter. Sampling points need not
be placed closer than 152 meters (500 feet) apart (or 76 meters (250
feet) if known sources are within 50 meters (162 feet) of the
monitoring perimeter), as long as a minimum of 3 monitoring
locations are used for each subarea.
    <IP_ADDRESS>.5 Sampling sites are not needed at the intersection of
an inner boundary with an adjacent subarea. The sampling location
must be sited where the measured angle intersects the subarea's
outer monitoring perimeter.

[GRAPHIC] [TIFF OMITTED] TR01DE15.028

    8.2.3 Option 2 for Determining Sampling Locations.
    <IP_ADDRESS> For facilities with a monitoring perimeter length of
less than 7,315 meters (24,000 feet), a minimum of twelve sampling
locations evenly spaced 10 percent of the location
interval is required.
    <IP_ADDRESS> For facilities with a monitoring perimeter length
greater than 7,315 meters (24,000 feet), sampling locations are
spaced 610 76 meters (2,000  250 feet)
apart.

8.3 Siting a Meteorological Station

    A meteorological station is required at or near the facility you
are monitoring. A number of commercially available meteorological
stations can be used. Information on meteorological instruments can
be found in EPA-454/R-99-005 (Reference 11) (incorporated by
reference--see Sec.  63.14). Some important considerations for
siting of meteorological stations are detailed below.
    8.3.1 Place meteorological stations in locations that represent
conditions affecting the transport and dispersion of pollutants in
the area of interest. Complex terrain may require the use of more
than one meteorological station.
    8.3.2 Deploy wind instruments over level, open terrain at a
height of 10 meters (33 feet). If possible, locate wind instruments
at a distance away from nearby structures that is equal to at least
10 times the height of the structure.
    8.3.3 Protect meteorological instruments from thermal radiation
and adequately ventilate them using aspirated shields. The
temperature sensor must be located at a distance away from any
nearby structures that is equal to at least four times the height of
the structure. Temperature sensors must be located at least 30
meters (98 feet) from large paved areas.
    8.3.4 Collect and record meteorological data, including wind
speed, wind direction, temperature and barometric pressure on an
hourly basis. Calculate average unit vector wind direction, sigma
theta, temperature and barometric pressure per sampling period to
enable calculation of concentrations at standard conditions. Supply
this information to the laboratory.
    8.3.5 Identify and record the location of the meteorological
station by its GPS coordinate.

8.4 Monitoring Frequency

    8.4.1 Sample collection may be performed for periods up to 14
days.
    8.4.2 A site screening protocol that meets method requirements
may be performed by collecting samples for a year where each PS
accumulates VOC for a 14-day sampling period. Study results are
accumulated for the sampling periods (typically 26) over the course
of one calendar year. To the extent practical, sampling tubes should
be changed at approximately the same time of day at each of the
monitoring sites.

8.5 Passive Sampler Deployment

    8.5.1 Clean (conditioned) sorbent tubes must be prepared and
packaged by the laboratory as described in Method 325B and must be
deployed for sampling within 30 days of conditioning.
    8.5.2 Allow the tubes to equilibrate with ambient temperature
(approximately 30 minutes to 1 hour) at the monitoring location
before removing them from their storage/shipping container for
sample collection.
    8.5.3 If there is any risk that the analytical equipment will
not meet the requirement to exclude contamination on outer tube
surfaces from the sample flow path (see Section 6.6 of Method 325B),
sample handlers must wear clean, white, cotton or powder-free
nitrile gloves during PS deployment and collection and throughout
any other tube handling operations.
    8.5.4 Inspect the sampling tubes immediately prior to
deployment. Ensure that they are intact, securely capped, and in
good condition. Any suspect tubes (e.g., tubes that appear to have
leaked sorbent) should be removed from the sampling set.
    8.5.5 Secure passive samplers so the bottom of the diffusive
sampling cap is 1.5 to 3 meters (4.9 to 9.8 feet) above ground using
a pole or other secure structure at each sampling location. Orient
the PS vertically and with the sampling end pointing downward to
avoid ingress of particulates.

    Note:  Duplicate sampling assemblies must be deployed in at
least one monitoring location for every 10 monitoring locations
during each field monitoring period.

    8.5.6 Protect the PS from rain and excessive wind velocity by
placing them under the type of protective hood described in Section
6.1.3 or equivalent.
    8.5.7 Remove the storage cap on the sampling end of the tube and
replace it with a diffusive sampling cap at the start of the
sampling period. Make sure the diffusion cap is properly seated and
store the removed storage caps in the empty tube shipping container.
    8.5.8 Record the start time and location details for each
sampler on the field sample data sheet (see example in Section
17.0.).

    8.5.9 Expose the sampling tubes for the required sampling
period-normally 14-days.
    8.5.10 Field blank tubes (see Section 9.3 of Method 325B) are
stored outside the shipping container at representative sampling
locations around the site, but with both long-term storage caps kept
in place throughout the monitoring exercise. Collect at least two
field blanks sorbent samples per sampling period to ensure sample
integrity associated with shipment, collection, and storage.

8.6 Sorbent Tube Recovery and Meteorological Data Collection

    Recover deployed sampling tubes and field blanks as follows:
    8.6.1 After the sampling period is complete, immediately replace
the diffusion end cap on each sampled tube with a long-term storage
end cap. Tighten the seal securely by hand and then tighten an
additional quarter turn with an appropriate tool. Record the stop
date and time and any additional relevant information on the sample
data sheet.
    8.6.2 Place the sampled tubes, together with the field blanks,
in the storage/shipping container. Label the storage container, but
do not use paints, markers, or adhesive labels to identify the
tubes. TD-compatible electronic (radio frequency identification
(RFID)) tube labels are available commercially and are compatible
with some brands of thermal desorber. If used, these may be
programmed with relevant tube and sample information, which can be
read and automatically transcribed into the sequence report by the
TD system.

    Note:  Sampled tubes must not be placed in the same shipping
container as clean conditioned sampling tubes.

    8.6.3 Sampled tubes may be shipped at ambient temperature to a
laboratory for sample analysis.
    8.6.4 Specify whether the tubes are field blanks or were used
for sampling and document relevant information for each tube using a
Chain of Custody form (see example in Section 17.0) that accompanies
the samples from preparation of the tubes through receipt for
analysis, including the following information: Unique tube
identification numbers for each sampled tube; the date, time, and
location code for each PS placement; the date, time, and location
code for each PS recovery; the GPS reference for each sampling
location; the unique identification number of the duplicate sample
(if applicable); and problems or anomalies encountered.
    8.6.5 If the sorbent tubes are supplied with electronic (e.g.,
RFID) tags, it is also possible to allocate a sample identifier to
each PS tube. In this case, the recommended format for the
identification number of each sampled tube is AA-BB-CC-DD-VOC,
where:

AA = Sequence number of placement on route (01, 02, 03 . . .)
BB = Sampling location code (01, 02, 03 . . .)
CC = 14-day sample period number (01 to 26)
DD = Sample code (SA = sample, DU = duplicate, FB = field blank)
VOC = 3-letter code for target compound(s) (e.g., BNZ for benzene or
BTX for benzene, toluene, and xylenes)

    Note:  Sampling start and end times/dates can also be logged
using RFID tube tags.

9.0 Quality Control

    9.1 Most quality control checks are carried out by the
laboratory and associated requirements are in Section 9.0 of Method
325B, including requirements for laboratory blanks, field blanks,
and duplicate samples.
    9.2 Evaluate for potential outliers the laboratory results for
neighboring sampling tubes collected over the same time period. A
potential outlier is a result for which one or more PS tube does not
agree with the trend in results shown by neighboring PS tubes--
particularly when data from those locations have been more
consistent during previous sampling periods. Accidental
contamination by the sample handler must be documented before any
result can be eliminated as an outlier. Rare but possible examples
of contamination include loose or missing storage caps or
contaminated storage/shipping containers. Review data from the same
and neighboring monitoring locations for the subsequent sampling
periods. If the anomalous result is not repeated for that monitoring
location, the episode can be ascribed to transient contamination and
the data in question must be flagged for potential elimination from
the dataset.

9.3 Duplicates and Field Blanks

    9.3.1 Collect at least one co-located/duplicate sample for every
10 field samples to determine precision of the measurements.
    9.3.2 Collect at least two field blanks sorbent samples per
sampling period to ensure sample integrity associated with shipment,
collection, and storage. You must use the entire sampling apparatus
for field blanks including unopened sorbent tubes mounted in
protective sampling hoods. The tube closures must not be removed.
Field blanks must be placed in two different quadrants (e.g.,
90[deg] and 270[deg]) and remain at the sampling location for the
sampling period.

10.0 Calibration and Standardization

    Follow the calibration and standardization procedures for
meteorological measurements in EPA-454/B-08-002 March 2008
(Reference 11) (incorporated by reference--see Sec.  63.14). Refer
to Method 325B for calibration and standardization procedures for
analysis of the passive sampling tubes.

11.0 Analytical Procedures

    Refer to Method 325B, which provides details for the preparation
and analysis of sampled passive monitoring tubes (preparation of
sampling tubes, shipment and storage of exposed sampling tubes, and
analysis of sampling tubes).

12.0 Data Analysis, Calculations and Documentation

12.1 Calculate Annual Average Fenceline Concentration.

    After a year's worth of sampling at the facility fenceline (for
example, 26 14-day samples), the average (PSi) may be
calculated for any specified period at each PS location using
Equation 12.1.
[GRAPHIC] [TIFF OMITTED] TR01DE15.029

Where:
PSi = Annual average for location i.
PSip = Sampling period specific concentration from Method
325B.
i = Location of passive sampler (0 to 360[deg]).
p = The sampling period.
N = The number of sampling periods in the year (e.g., for 14-day
sampling periods, from 1 to 26).

    Note:  PSip is a function of sampling location-
specific factors such as the contribution from facility sources,
unusual localized meteorological conditions, contribution from
nearby interfering sources, the background caused by integrated far-
field sources and measurement error due to deployment, handling,
siting, or analytical errors.

12.2 Identify Sampling Locations of Interest

    If data from neighboring sampling locations are significantly
different, then you may add extra sampling points to isolate
background contributions or identify facility-specific ``hot
spots.''

12.3 Evaluate Trends

    You may evaluate trends and patterns in the PS data over
multiple sampling periods to determine if elevated concentrations of
target compounds are due to operations on the facility or if
contributions from background sources are significant.
    12.3.1 Obtain meteorological data including wind speed and wind
direction or unit vector wind data from the on-site meteorological
station. Use this meteorological data to determine the prevailing
wind direction and speed during the periods of elevated
concentrations.
    12.3.2 As an option you may perform preliminary back trajectory
calculations (http://ready.arl.noaa.gov/HYSPLIT.php) to aid in
identifying the source of the background contribution to elevated
target compound concentrations.

    12.3.3 Information on published or documented events on- and
off-site may also be included in the associated sampling period
report to explain elevated concentrations if relevant. For example,
you would describe if there was a chemical spill on site, or an
accident on an adjacent road.
    12.3.4 Additional monitoring for shorter periods (See section
8.4) may be necessary to allow better discrimination/resolution of
contributing emission sources if the measured trends and associated
meteorology do not provide a clear assessment of facility
contribution to the measured fenceline concentration.
    12.3.5 Additional records necessary to calculate sampling period
average target compound concentration can be found in Section 12.1
of Method 325B.

13.0 Method Performance

    Method performance requirements are described in Method 325B.

14.0 Pollution Prevention

    [Reserved]

15.0 Waste Management

    [Reserved]

16.0 References

1. Ambient air quality--Standard method for measurement of benzene
concentrations--Part 4: Diffusive sampling followed by thermal
desorption and gas chromatography, BS EN 14662-4:2005.
2. Thoma, E.D., Miller, C.M., Chung, K.C., Parsons, N.L. and Shine,
B.C. Facility Fence Line Monitoring using Passive Samplers, J. Air &
Waste Mange. Assoc. 2011, 61:834-842.
3. Quality Assurance Handbook for Air Pollution C Systems, Volume
II: Ambient Air Quality Monitoring Program, EPA-454/B-13-003, May
2013. Available at http://www.epa.gov/ttnamti1/files/ambient/pm25/qa/QA-Handbook-Vol-II.pdf.
4. Brown, R.H., Charlton, J. and Saunders, K.J.: The development of
an improved diffusive sampler. Am. Ind. Hyg. Assoc. J. 1981, 42(12):
865-869.
5. Brown, R. H. Environmental use of diffusive samplers: evaluation
of reliable diffusive uptake rates for benzene, toluene and xylene.
J. Environ. Monit. 1999, 1 (1), 115-116.
6. Ballach, J.; Greuter, B.; Schultz, E.; Jaeschke, W. Variations of
uptake rates in benzene diffusive sampling as a function of ambient
conditions. Sci. Total Environ. 1999, 244, 203-217.
7. Brown, R. H. Monitoring the ambient environment with diffusive
samplers: theory and practical considerations. J Environ. Monit.
2000, 2 (1), 1-9.
8. Buzica, D.; Gerboles, M.; Plaisance, H. The equivalence of
diffusive samplers to reference methods for monitoring
O3, benzene and NO2 in ambient air. J.
Environ. Monit. 2008, 10 (9), 1052-1059.
9. Woolfenden, E. Sorbent-based sampling methods for volatile and
semi-volatile organic compounds in air. Part 2. Sorbent selection
and other aspects of optimizing air monitoring methods. J.
Chromatogr. A 2010, 1217, (16), 2685-94.
10. Pfeffer, H. U.; Breuer, L. BTX measurements with diffusive
samplers in the vicinity of a cokery: Comparison between ORSA-type
samplers and pumped sampling. J. Environ. Monit. 2000, 2 (5), 483-
486.
11. US EPA. 2000. Meteorological Monitoring Guidance for Regulatory
Modeling Applications. EPA-454/R-99-005. Office of Air Quality
Planning and Standards, Research Triangle Park, NC. February 2000.
Available at http://www.epa.gov/scram001/guidance/met/mmgrma.pdf.
12. Quality Assurance Handbook for Air Pollution Measurement
Systems. Volume IV: Meteorological Measurements Version 2.0 Final,
EPA-454/B-08-002 March 2008. Available at http://www.epa.gov/ttnamti1/files/ambient/met/Volume%20IV_Meteorological_Measurements.pdf.
13. ISO 16017-2:2003(E), Indoor, ambient and workplace air--Sampling
and analysis of volatile organic compounds by sorbent tube/thermal
desorption/capillary gas chromatography. Part 2: Diffusive sampling.
14. ASTM D6196-03 (Reapproved 2009): Standard practice for selection
of sorbents, sampling, and thermal desorption analysis procedures
for volatile organic compounds in air.

17.0 Tables, Diagrams, Flowcharts and Validation Data

[GRAPHIC] [TIFF OMITTED] TR01DE15.030

Method 325B--Volatile Organic Compounds from Fugitive and Area Sources:

Sampler Preparation and Analysis

1.0 Scope and Application

    1.1 This method describes thermal desorption/gas chromatography
(TD/GC) analysis of volatile organic compounds (VOCs) from fugitive
and area emission sources collected onto sorbent tubes using passive
sampling. It could also be applied to the TD/GC analysis of VOCs
collected using active (pumped) sampling onto sorbent tubes. The
concentration of airborne VOCs at or near potential fugitive- or
area-emission sources may be determined using this method in
combination with Method 325A. Companion Method 325A (Sampler
Deployment and VOC Sample Collection) describes procedures for
deploying the sorbent tubes and passively collecting VOCs.
    1.2 The preferred GC detector for this method is a mass
spectrometer (MS), but flame ionization detectors (FID) may also be
used. Other conventional GC detectors such as electron capture
(ECD), photoionization (PID), or flame photometric (FPD) may also be
used if they are selective and sensitive to the target compound(s)
and if they meet the method performance criteria provided in this
method.
    1.3 There are 97 VOCs listed as hazardous air pollutants in
Title III of the Clean Air Act Amendments of 1990. Many of these VOC
are candidate compounds for this method. Compounds with known uptake
rates for CarbographTM 1 TD, CarbopackTM B, or
CarbopackTM X are listed in Table 12.1. This method
provides performance criteria to demonstrate acceptable performance
of the method (or modifications of the method) for monitoring one or
more of the compounds listed Table 12.1. If standard passive
sampling tubes are packed with other sorbents or used for other
analytes than those listed in Table 12.1, then method performance
and relevant uptake rates should be verified according to Addendum A
to this method or by one of the following national/international
standard methods: ISO 16017-2:2003(E), ASTM D6196-03 (Reapproved
2009), or BS EN 14662-4:2005 (all incorporated by reference--see
Sec.  63.14), or reported in the peer-reviewed open literature.
    1.4 The analytical approach using TD/GC/MS is based on
previously published EPA guidance in Compendium Method TO-17 (http://www.epa.gov/ttnamti1/airtox.html#compendium) (Reference 1), which
describes active (pumped) sampling of VOCs from ambient air onto
tubes packed with thermally stable adsorbents.
    1.5 Inorganic gases not suitable for analysis by this method
include oxides of carbon, nitrogen and sulfur, ozone
(O3), and other diatomic permanent gases. Other
pollutants not suitable for this analysis method include particulate
pollutants, (i.e., fumes, aerosols, and dusts), compounds too labile
(reactive) for conventional GC analysis, and VOCs that are more
volatile than propane.

2.0 Summary of Method

    2.1 This method provides procedures for the preparation,
conditioning, blanking, and shipping of sorbent tubes prior to
sample collection.
    2.2 Laboratory and field personnel must have experience of
sampling trace-level VOCs using sorbent tubes (References 2,5) and
must have experience operating thermal desorption/GC/multi-detector
instrumentation.
    2.3 Key steps of this method as implemented for each sample tube
include: Stringent leak testing under stop flow, recording ambient
temperature conditions, adding internal standards, purging the tube,
thermally desorbing the sampling tube, refocusing on a focusing
trap, desorbing and transferring/injecting the VOCs from the
secondary trap into the capillary GC column for separation and
analysis.
    2.4 Water management steps incorporated into this method
include: (a) Selection of hydrophobic sorbents in the sampling tube;
(b) optional dry purging of sample tubes prior to analysis; and (c)
additional selective elimination of water during primary (tube)
desorption (if required) by selecting trapping sorbents and
temperatures such that target compounds are quantitatively retained
while water is purged to vent.

3.0 Definitions

    (See also Section 3.0 of Method 325A).
    3.1 Blanking is the desorption and confirmatory analysis of
conditioned sorbent tubes before they are sent for field sampling.
    3.2 Breakthrough volume and associated relation to passive
sampling. Breakthrough volumes, as applied to active sorbent tube
sampling, equate to the volume of air containing a constant
concentration of analyte that may be passed through a sorbent tube
at a given temperature before a detectable level (5 percent) of the
input analyte concentration elutes from the tube. Although
breakthrough volumes are directly related to active rather than
passive sampling, they provide a measure of the strength of the
sorbent-sorbate interaction and therefore also relate to the
efficiency of the passive sampling process. The best direct measure
of passive sampling efficiency is the stability of the uptake rate.
Quantitative passive sampling is compromised when the sorbent no
longer acts as a perfect sink--i.e., when the concentration of a
target analyte immediately above the sorbent sampling surface no
longer approximates to zero. This causes a reduction in the uptake
rate over time. If the uptake rate for a given analyte on a given
sorbent tube remains relatively constant --i.e., if the uptake rate
determined for 48 hours is similar to that determined for 7 or 14
days--the user can be confident that passive sampling is occurring
at a constant rate. As a general rule of thumb, such ideal passive
sampling conditions typically exist for analyte:sorbent combinations
where the breakthrough volume exceeds 100 L (Reference 4).
    3.3 Continuing calibration verification sample (CCV). Single
level calibration samples run periodically to confirm that the
analytical system continues to generate sample results within
acceptable agreement to the current calibration curve.
    3.4 Focusing trap is a cooled, secondary sorbent trap integrated
into the analytical thermal desorber. It typically has a smaller
i.d. and lower thermal mass than the original sample tube allowing
it to effectively refocus desorbed analytes and then heat rapidly to
ensure efficient transfer/injection into the capillary GC analytical
column.
    3.5 High Resolution Capillary Column Chromatography uses fused
silica capillary columns with an inner diameter of 320 [mu]m or less
and with a stationary phase film thickness of 5 [mu]m or less.
    3.6 h is time in hours.
    3.7 i.d. is inner diameter.
    3.8 min is time in minutes.
    3.9 Method Detection Limit is the lowest level of analyte that
can be detected in the sample matrix with 99% confidence.
    3.10 MS-SCAN is the mode of operation of a GC quadrupole mass
spectrometer detector that measures all ions over a given mass range
over a given period of time.
    3.11 MS-SIM is the mode of operation of a GC quadrupole mass
spectrometer detector that measures only a single ion or a selected
number of discrete ions for each analyte.
    3.12 o.d. is outer diameter.
    3.13 ppbv is parts per billion by volume.
    3.14 Thermal desorption is the use of heat and a flow of inert
(carrier) gas to extract volatiles from a solid matrix. No solvent
is required.
    3.15 Total ion chromatogram is the chromatogram produced from a
mass spectrometer detector collecting full spectral information.
    3.16 Two-stage thermal desorption is the process of thermally
desorbing analytes from a sorbent tube, reconcentrating them on a
focusing trap (see Section 3.4), which is then itself rapidly heated
to ``inject'' the concentrated compounds into the GC analyzer.
    3.17 VOC is volatile organic compound.

4.0 Analytical Interferences

    4.1 Interference from Sorbent Artifacts. Artifacts may include
target analytes as well as other VOC that co-elute
chromatographically with the compounds of interest or otherwise
interfere with the identification or quantitation of target
analytes.
    4.1.1 Sorbent decomposition artifacts are VOCs that form when
sorbents degenerate, e.g., when exposed to reactive species during
sampling. For example, benzaldehyde, phenol, and acetophenone
artifacts are reported to be formed via oxidation of the polymeric
sorbent Tenax[supreg] when sampling high concentration (100-500 ppb)
ozone atmospheres (Reference 5).
    4.1.2 Preparation and storage artifacts are VOCs that were not
completely cleaned from the sorbent tube during conditioning or that
are an inherent feature of that sorbent at a given temperature.
    4.2 Humidity. Moisture captured during sampling can interfere
with VOC analysis. Passive sampling using tubes packed with
hydrophobic sorbents, like those described in this method, minimizes
water retention. However, if water interference is found to be an
issue under extreme conditions, one or more of the water management
steps described in Section 2.4 can be applied.
    4.3 Contamination from Sample Handling. The type of analytical
thermal

desorption equipment selected should exclude the possibility of
outer tube surface contamination entering the sample flow path (see
Section 6.6). If the available system does not meet this
requirement, sampling tubes and caps must be handled only while
wearing clean, white cotton or powder free nitrile gloves to prevent
contamination with body oils, hand lotions, perfumes, etc.

5.0 Safety

    5.1 This method does not address all of the safety concerns
associated with its use. It is the responsibility of the user of
this standard to establish appropriate field and laboratory safety
and health practices prior to use.
    5.2 Laboratory analysts must exercise extreme care in working
with high-pressure gas cylinders.
    5.3 Due to the high temperatures involved, operators must use
caution when conditioning and analyzing tubes.

6.0 Equipment and Supplies

    6.1 Tube Dimensions and Materials. The sampling tubes for this
method are 3.5-inches (89 mm) long, \1/4\ inch (6.4 mm) o.d., and 5
mm i.d. passive sampling tubes (see Figure 6.1). The tubes are made
of inert-coated stainless steel with the central section (up to 60
mm) packed with sorbent, typically supported between two 100 mesh
stainless steel gauze. The tubes have a cross sectional area of 19.6
square mm (5 mm i.d.). When used for passive sampling, these tubes
have an internal diffusion (air) gap (DG) of 1.5 cm between the
sorbent retaining gauze at the sampling end of the tube, and the
gauze in the diffusion cap.
[GRAPHIC] [TIFF OMITTED] TR01DE15.031

6.2 Tube Conditioning Apparatus

    6.2.1 Freshly packed or newly purchased tubes must be
conditioned as described in Section 9 using an appropriate dedicated
tube conditioning unit or the thermal desorber. Note that the
analytical TD system should be used for tube conditioning if it
supports a dedicated tube conditioning mode in which effluent from
contaminated tubes is directed to vent without passing through key
parts of the sample flow path such as the focusing trap.
    6.2.2 Dedicated tube conditioning units must be leak-tight to
prevent air ingress, allow precise and reproducible temperature
selection (5 [deg]C), offer a temperature range at least
as great as that of the thermal desorber, and support inert gas
flows in the range up to 100 mL/min.

    Note: For safety and to avoid laboratory contamination, effluent
gases from freshly packed or highly contaminated tubes should be
passed through a charcoal filter during the conditioning process to
prevent desorbed VOCs from polluting the laboratory atmosphere.

6.3 Tube Labeling

    6.3.1 Label the sample tubes with a unique permanent
identification number and an indication of the sampling end of the
tube. Labeling options include etching and TD-compatible electronic
(radio frequency identification (RFID)) tube labels.
    6.3.2 To avoid contamination, do not make ink markings of any
kind on clean sorbent tubes or apply adhesive labels.

    Note: TD-compatible electronic (RFID) tube labels are available
commercially and are compatible with some brands of thermal
desorber. If used, these may be programmed with relevant tube and
sample information, which can be read and automatically transcribed
into the sequence report by the TD system (see Section 8.6 of Method
325A).

6.4 Blank and Sampled Tube Storage Apparatus

    6.4.1 Long-term storage caps. Seal clean, blank and sampled
sorbent tubes using inert, long-term tube storage caps comprising
non-greased, 2-piece, 0.25-inch, metal SwageLok[supreg]-type screw
caps fitted with combined polytetrafluoroethylene ferrules.
    6.4.2 Storage and transportation containers. Use clean glass
jars, metal cans or rigid, non-emitting polymer boxes.

    Note:  You may add a small packet of new activated charcoal or
charcoal/silica gel to the shipping container for storage and
transportation of batches of conditioned sorbent tubes prior to use.
Coolers without ice packs make suitable shipping boxes for
containers of tubes because the coolers help to insulate the samples
from extreme temperatures (e.g., if left in a parked vehicle).

6.5 Unheated GC Injection Unit for Loading Standards Onto Blank Tubes

    A suitable device has a simple push fit or finger-tightening
connector for attaching the sampling end of blank sorbent tubes
without damaging the tube. It also has a means of controlling
carrier gas flow through the injector and attached sorbent tube at
50-100 mL/min and includes a low emission septum cap that allows the
introduction of gas or liquid standards via appropriate syringes.
Reproducible and quantitative transfer of higher boiling compounds
in liquid standards is facilitated if the injection unit allows the
tip of the syringe to just touch the sorbent retaining gauze inside
the tube.

6.6 Thermal Desorption Apparatus

    The manual or automated thermal desorption system must heat
sorbent tubes while a controlled flow of inert (carrier) gas passes
through the tube and out of the sampling end. The apparatus must
also incorporate a focusing trap to quantitatively refocus compounds
desorbed from the tube. Secondary desorption of the focusing trap
should be fast/efficient enough to transfer the compounds into the
high resolution capillary GC column without band broadening and
without any need for further pre- or on-column focusing. Typical TD
focusing traps comprise small sorbent traps (Reference 16) that are
electrically-cooled using multistage Peltier cells (References 17,
18). The direction of gas flow during trap desorption should be the
reverse of that used for focusing to extend the compatible analyte
volatility range. Closed cycle coolers offer another cryogen-free
trap cooling option. Other TD system requirements and operational
stages are described in Section 11 and in Figures 17-2 through 17-4.

6.7 Thermal Desorber--GC Interface

    6.7.1 The interface between the thermal desorber and the GC must
be heated uniformly and the connection between the transfer line
insert and the capillary GC analytical column itself must be leak
tight.
    6.7.2 A portion of capillary column can alternatively be
threaded through the heated transfer line/TD interface and connected
directly to the thermal desorber.

    Note:  Use of a metal syringe-type needle or unheated length of
fused silica pushed through the septum of a conventional GC

injector is not permitted as a means of interfacing the thermal
desorber to the chromatograph. Such connections result in cold
spots, cause band broadening and are prone to leaks.

6.8 GC/MS Analytical Components

    6.8.1 The GC system must be capable of temperature programming
and operation of a high resolution capillary column. Depending on
the choice of column (e.g., film thickness) and the volatility of
the target compounds, it may be necessary to cool the GC oven to
subambient temperatures (e.g., -50 [deg]C) at the start of the run
to allow resolution of very volatile organic compounds.
    6.8.2 All carrier gas lines supplying the GC must be constructed
from clean stainless steel or copper tubing. Non-
polytetrafluoroethylene thread sealants. Flow controllers, cylinder
regulators, or other pneumatic components fitted with rubber
components are not suitable.

6.9 Chromatographic Columns

    High-resolution, fused silica or equivalent capillary columns
that provide adequate separation of sample components to permit
identification and quantitation of target compounds must be used.

    Note:  100-percent methyl silicone or 5-percent phenyl, 95-
percent methyl silicone fused silica capillary columns of 0.25- to
0.32-mm i.d. of varying lengths and with varying thicknesses of
stationary phase have been used successfully for non-polar and
moderately polar compounds. However, given the diversity of
potential target lists, GC column choice is left to the operator,
subject to the performance criteria of this method.

6.10 Mass Spectrometer

    Linear quadrupole, magnetic sector, ion trap or time-of-flight
mass spectrometers may be used provided they meet specified
performance criteria. The mass detector must be capable of
collecting data from 35 to 300 atomic mass units (amu) every 1
second or less, utilizing 70 volts (nominal) electron energy in the
electron ionization mode, and producing a mass spectrum that meets
all the instrument performance acceptance criteria in Section 9 when
50 [eta]g or less of p-bromofluorobenzene is analyzed.

7.0 Reagents and Standards

7.1 Sorbent Selection

    7.1.1 Use commercially packed tubes meeting the requirements of
this method or prepare tubes in the laboratory using sieved sorbents
of particle size in the range 20 to 80 mesh that meet the retention
and quality control requirements of this method.
    7.1.2 This passive air monitoring method can be used without the
evaluation specified in Addendum A if the type of tubes described in
Section 6.1 are packed with 4-6 cm (typically 400-650 mg) of the
sorbents listed in Table 12.1 and used for the respective target
analytes.

    Note:  Although CarbopackTM X is the optimum sorbent
choice for passive sampling of 1,3-butadiene, recovery of compounds
with vapor pressure lower than benzene may be difficult to achieve
without exceeding sorbent maximum temperature limitations (see Table
8.1). See ISO 16017-2:2003(E) or ASTM D6196-03 (Reapproved 2009)
(both incorporated by reference--see Sec.  63.14) for more details
on sorbent choice for air monitoring using passive sampling tubes.

    7.1.3 If standard passive sampling tubes are packed with other
sorbents or used for analytes other than those tabulated in Section
12.0, method performance and relevant uptake rates should be
verified according to Addendum A to this method or by following the
techniques described in one of the following national/international
standard methods: ISO 16017-2:2003(E), ASTM D6196-03 (Reapproved
2009), or BS EN 14662-4:2005 (all incorporated by reference--see
Sec.  63.14)--or reported in the peer-reviewed open literature. A
summary table and the supporting evaluation data demonstrating the
selected sorbent meets the requirements in Addendum A to this method
must be submitted to the regulatory authority as part of a request
to use an alternative sorbent.
    7.1.4 Passive (diffusive) sampling and thermal desorption
methods that have been evaluated at relatively high atmospheric
concentrations (i.e., mid-ppb to ppm) and published for use in
workplace air and industrial/mobile source emissions testing
(References 9-20) may be applied to this procedure. However, the
validity of any shorter term uptake rates must be verified and
adjusted if necessary for the longer monitoring periods required by
this method by following procedures described in Addendum A to this
method or those presented in national/international standard
methods: ISO 16017-2:2003(E), ASTM D6196-03 (Reapproved 2009), or BS
EN 14662-4:2005 (all incorporated by reference-see Sec.  63.14).
    7.1.5 Suitable sorbents for passive sampling must have
breakthrough volumes of at least 20 L (preferably >100 L) for the
compounds of interest and must quantitatively release the analytes
during desorption without exceeding maximum temperatures for the
sorbent or instrumentation.
    7.1.6 Repack/replace the sorbent tubes or demonstrate tube
performance following the requirements in Addendum A to this method
at least every 2 years or every 50 uses, whichever occurs first.

7.2 Gas Phase Standards

    7.2.1 Static or dynamic standard atmospheres may be used to
prepare calibration tubes and/or to validate passive sampling uptake
rates and can be generated from pure chemicals or by diluting
concentrated gas standards. The standard atmosphere must be stable
at ambient pressure and accurate to 10 percent of the
target gas concentration. It must be possible to maintain standard
atmosphere concentrations at the same or lower levels than the
target compound concentration objectives of the test. Test
atmospheres used for validation of uptake rates must also contain at
least 35 percent relative humidity.

    Note:  Accurate, low-(ppb-) level gas-phase VOC standards are
difficult to generate from pure materials and may be unstable
depending on analyte polarity and volatility. Parallel monitoring of
vapor concentrations with alternative methods, such as pumped
sorbent tubes or sensitive/selective on-line detectors, may be
necessary to minimize uncertainty. For these reasons, standard
atmospheres are rarely used for routine calibration.

    7.2.2 Concentrated, pressurized gas phase standards. Accurate
(5 percent or better), concentrated gas phase standards
supplied in pressurized cylinders may also be used for calibration.
The concentration of the standard should be such that a 0.5-5.0 mL
volume contains approximately the same mass of analytes as will be
collected from a typical air sample.
    7.2.3 Follow manufacturer's guidelines concerning storage
conditions and recertification of the concentrated gas phase
standard. Gas standards must be recertified a minimum of once every
12 months.

7.3 Liquid Standards

    Target analytes can also be introduced to the sampling end of
sorbent tubes in the form of liquid calibration standards.
    7.3.1 The concentration of liquid standards must be such that an
injection of 0.5-2 [micro]l of the solution introduces the same mass
of target analyte that is expected to be collected during the
passive air sampling period.
    7.3.2 Solvent Selection. The solvent selected for the liquid
standard must be pure (contaminants <10 percent of minimum analyte
levels) and must not interfere chromatographically with the
compounds of interest.
    7.3.3 If liquid standards are sourced commercially, follow
manufacturer's guidelines concerning storage conditions and shelf
life of unopened and opened liquid stock standards.

    Note: Commercial VOC standards are typically supplied in
volatile or non-interfering solvents such as methanol.

    7.3.4 Working standards must be stored at 6 [deg]C or less and
used or discarded within two weeks of preparation.

7.4 Gas Phase Internal Standards

    7.4.1 Gas-phase deuterated or fluorinated organic compounds may
be used as internal standards for MS-based systems.
    7.4.2 Typical compounds include deuterated toluene,
perfluorobenzene and perfluorotoluene.
    7.4.3 Use multiple internal standards to cover the volatility
range of the target analytes.
    7.4.4 Gas-phase standards must be obtained in pressurized
cylinders and containing vendor certified gas concentrations
accurate to 5 percent. The concentration should be such
that the mass of internal standard components introduced is similar
to those of the target analytes collected during field monitoring.

7.5 Preloaded Standard Tubes

    Certified, preloaded standard tubes, accurate within 5 percent for each analyte at the microgram level and 10 percent at the nanogram level, are available commercially

and may be used for auditing and quality control purposes. (See
Section 9.5 for audit accuracy evaluation criteria.) Certified
preloaded tubes may also be used for routine calibration.

    Note:  Proficiency testing schemes are also available for TD/GC/
MS analysis of sorbent tubes preloaded with common analytes such as
benzene, toluene, and xylene.

7.6 Carrier Gases

    Use inert, 99.999-percent or higher purity helium as carrier
gas. Oxygen and organic filters must be installed in the carrier gas
lines supplying the analytical system according to the
manufacturer's instructions. Keep records of filter and oxygen
scrubber replacement.

8.0 Sorbent Tube Handling (Before and After Sampling)

8.1 Sample Tube Conditioning

    8.1.1 Sampling tubes must be conditioned using the apparatus
described in Section 6.2.
    8.1.2 New tubes should be conditioned for 2 hours to supplement
the vendor's conditioning procedure. Recommended temperatures for
tube conditioning are given in Table 8.1.
    8.1.3 After conditioning, the blank must be verified on each new
sorbent tube and on 10 percent of each batch of reconditioned tubes.
See Section 9.0 for acceptance criteria.

                             Table 8.1--Example Sorbent Tube Conditioning Parameters
----------------------------------------------------------------------------------------------------------------
                                                                      Maximum      Conditioning
                        Sampling sorbent                            temperature     temperature     Carrier gas
                                                                     ([deg]C)        ([deg]C)        flow rate
----------------------------------------------------------------------------------------------------------------
Carbotrap[supreg] C.............................................            >400             350      100 mL/min
CarbopackTM C
Anasorb[supreg] GCB2
CarbographTM 1 TD
Carbotrap[supreg]
CarbopackTM B
Anasorb[supreg] GCB1
Tenax[supreg] TA                                                             350             330      100 mL/min
CarbopackTM X...................................................
----------------------------------------------------------------------------------------------------------------

8.2 Capping, Storage and Shipment of Conditioned Tubes

    8.2.1 Conditioned tubes must be sealed using long-term storage
caps (see Section 6.4) pushed fully down onto both ends of the PS
sorbent tube, tightened by hand and then tighten an additional
quarter turn using an appropriate tool.
    8.2.2 The capped tubes must be kept in appropriate containers
for storage and transportation (see Section 6.4.2). Containers of
sorbent tubes may be stored and shipped at ambient temperature and
must be kept in a clean environment.
    8.2.3 You must keep batches of capped tubes in their shipping
boxes or wrap them in uncoated aluminum foil before placing them in
their storage container, especially before air freight, because the
packaging helps hold caps in position if the tubes get very cold.

8.3 Calculating the Number of Tubes Required for a Monitoring Exercise

    8.3.1 Follow guidance given in Method 325A to determine the
number of tubes required for site monitoring.
    8.3.2 The following additional samples will also be required:
Laboratory blanks as specified in Section 9.1.2 (one per analytical
sequence minimum), field blanks as specified in Section 9.3.2 (two
per sampling period minimum), CCV tubes as specified in Section
10.9.4. (at least one per analysis sequence or every 24 hours), and
duplicate samples as specified in Section 9.4 (at least one
duplicate sample is required for every 10 sampling locations during
each monitoring period).

8.4 Sample Collection

    8.4.1 Allow the tubes to equilibrate with ambient temperature
(approximately 30 minutes to 1 hour) at the monitoring location
before removing them from their storage/shipping container for
sample collection.
    8.4.2 Tubes must be used for sampling within 30 days of
conditioning (Reference 4).
    8.4.3 During field monitoring, the long-term storage cap at the
sampling end of the tube is replaced with a diffusion cap and the
whole assembly is arranged vertically, with the sampling end
pointing downward, under a protective hood or shield--See Section
6.1 of Method 325A for more details.

8.5 Sample Storage

    8.5.1 After sampling, tubes must be immediately resealed with
long-term storage caps and placed back inside the type of storage
container described in Section 6.4.2.
    8.5.2 Exposed tubes may not be placed in the same container as
clean tubes. They should not be taken back out of the container
until ready for analysis and after they have had time to equilibrate
with ambient temperature in the laboratory.
    8.5.3 Sampled tubes must be inspected before analysis to
identify problems such as loose or missing caps, damaged tubes,
tubes that appear to be leaking sorbent or container contamination.
Any and all such problems must be documented together with the
unique identification number of the tube or tubes concerned.
Affected tubes must not be analyzed but must be set aside.
    8.5.4 Intact tubes must be analyzed within 30 days of the end of
sample collection (within one week for limonene, carene, bis-
chloromethyl ether, labile sulfur or nitrogen-containing compounds,
and other reactive VOCs).

    Note: Ensure ambient temperatures stay below 23 [deg]C during
transportation and storage. Refrigeration is not normally required
unless the samples contain reactive compounds or cannot be analyzed
within 30 days. If refrigeration is used, the atmosphere inside the
refrigerator must be clean and free of organic solvents.

9.0 Quality Control

9.1 Laboratory Blank

    The analytical system must be demonstrated to be contaminant
free by performing a blank analysis at the beginning of each
analytical sequence to demonstrate that the secondary trap and TD/
GC/MS analytical equipment are free of any significant interferents.
    9.1.1 Laboratory blank tubes must be prepared from tubes that
are identical to those used for field sampling.
    9.1.2 Analysis of at least one laboratory blank is required per
analytical sequence. The laboratory blank must be stored in the
laboratory under clean, controlled ambient temperature conditions.
    9.1.3 Laboratory blank/artifact levels must meet the
requirements of Section 9.2.2 (see also Table 17.1). If the
laboratory blank does not meet requirements, stop and perform
corrective actions and then re-analyze laboratory blank to ensure it
meets requirements.

9.2 Tube Conditioning

    9.2.1 Conditioned tubes must be demonstrated to be free of
contaminants and interference by running 10 percent of the blank
tubes selected at random from each conditioned batch under standard
sample analysis conditions (see Section 8.1).
    9.2.2 Confirm that artifacts and background contamination are <=
0.2 ppbv or less than three times the detection limit of the
procedure or less than 10 percent of the target compound(s) mass
that would be collected if airborne concentrations were at the
regulated limit value, whichever is larger. Only tubes that meet
these criteria can be

used for field monitoring, field or laboratory blanks, or for system
calibration.
    9.2.3 If unacceptable levels of VOCs are observed in the tube
blanks, then the processes of tube conditioning and checking the
blanks must be repeated.

9.3 Field Blanks

    9.3.1 Field blank tubes must be prepared from tubes that are
identical to those used for field sampling--i.e., they should be
from the same batch, have a similar history, and be conditioned at
the same time.
    9.3.2 Field blanks must be shipped to the monitoring site with
the sampling tubes and must be stored at the sampling location
throughout the monitoring exercise. The field blanks must be
installed under a protective hood/cover at the sampling location,
but the long-term storage caps must remain in place throughout the
monitoring period (see Method 325A). The field blanks are then
shipped back to the laboratory in the same container as the sampled
tubes. One field blank tube is required for every 10 sampled tubes
on a monitoring exercise and no less than two field blanks should be
collected, regardless of the size of the monitoring study.
    9.3.3 Field blanks must contain no greater than one-third of the
measured target analyte or compliance limit for field samples (see
Table 17.1). If either field blank fails, flag all data that do not
meet this criterion with a note that the associated results are
estimated and likely to be biased high due to field blank
background.

9.4 Duplicate Samples

    Duplicate (co-located) samples collected must be analyzed and
reported as part of method quality control. They are used to
evaluate sampling and analysis precision. Relevant performance
criteria are given in Section 9.9.

9.5 Method Performance Criteria

    Unless otherwise noted, monitoring method performance
specifications must be demonstrated for the target compounds using
the procedures described in Addendum A to this method and the
statistical approach presented in Method 301.

9.6 Method Detection Limit

    Determine the method detection limit under the analytical
conditions selected (see Section 11.3) using the procedure in
Section 15 of Method 301. The method detection limit is defined for
each system by making seven replicate measurements of a
concentration of the compound of interest within a factor of five of
the detection limit. Compute the standard deviation for the seven
replicate concentrations, and multiply this value by three. The
results should demonstrate that the method is able to detect
analytes such as benzene at concentrations as low as 50 ppt or 1/3rd
(preferably 1/10th) of the lowest concentration of interest,
whichever is larger.

    Note:  Determining the detection limit may be an iterative
process as described in 40 CFR part 136, Appendix B.

9.7 Analytical Bias

     Analytical bias must be demonstrated to be within 30 percent using Equation 9.1. Analytical bias must be
demonstrated during initial setup of this method and as part of the
CCV carried out with every sequence of 10 samples or less (see
Section 9.14). Calibration standard tubes (see Section 10.0) may be
used for this purpose.

[GRAPHIC] [TIFF OMITTED] TR01DE15.032

 Eq. 9.1Where:

Spiked Value = A known mass of VOCs added to the tube.
Measured Value = Mass determined from analysis of the tube.

9.8 Analytical Precision

    Demonstrate an analytical precision within 20
percent using Equation 9.2. Analytical precision must be
demonstrated during initial setup of this method and at least once
per year. Calibration standard tubes may be used (see Section 10.0)
and data from CCV may also be applied for this purpose.
[GRAPHIC] [TIFF OMITTED] TR01DE15.033

Eq. 9.2Where:

A1 = A measurement value taken from one spiked tube.
A2 = A measurement value taken from a second spiked tube.
A = The average of A1 and A2.

9.9 Field Replicate Precision

    Use Equation 9.3 to determine and report replicate precision for
duplicate field samples (see Section 9.4). The level of agreement
between duplicate field samples is a measure of the precision
achievable for the entire sampling and analysis procedure. Flag data
sets for which the duplicate samples do not agree within 30 percent.
[GRAPHIC] [TIFF OMITTED] TR01DE15.034

 Eq. 9.3Where:
F1 = A measurement value (mass) taken from one of the two field
replicate tubes used in sampling.
F2 = A measurement value (mass) taken from the second of two field
replicate tubes used in sampling.
F = The average of F1 and F2.

9.10 Desorption Efficiency and Compound Recovery

    The efficiency of the thermal desorption method must be
determined.
    9.10.1 Quantitative (>95 percent) compound recovery must be
demonstrated by repeat analyses on a same standard tube.
    9.10.2 Compound recovery through the TD system can also be
demonstrated by comparing the calibration check sample response
factor obtained from direct GC injection of liquid standards with
that obtained from thermal desorption analysis response factor using
the same column under identical conditions.
    9.10.3 If the relative response factors obtained for one or more
target compounds introduced to the column via thermal desorption
fail to meet the criteria in Section 9.10.1, you must adjust the TD
parameters to meet the criteria and repeat the experiment. Once the
thermal desorption conditions have been optimized, you must repeat
this test each time the analytical system is recalibrated to
demonstrate continued method performance.

9.11 Audit Samples

    Certified reference standard samples must be used to audit this
procedure (if available). Accuracy within 30 percent must be

demonstrated for relevant ambient air concentrations (0.5 to 25
ppb).

9.12 Mass Spectrometer Tuning Criteria

    Tune the mass spectrometer (if used) according to manufacturer's
specifications. Verify the instrument performance by analyzing a 50
[eta]g injection of bromofluorobenzene. Prior to the beginning of
each analytical sequence or every 24 hours during continuous GC/MS
operation for this method demonstrate that the bromofluorobenzene
tuning performance criteria in Table 9.1 have been met.

                                      Table 9.1--GC/MS Tuning Criteria \1\
----------------------------------------------------------------------------------------------------------------
                           Target mass                             Rel. to mass    Lower limit %   Upper limit %
----------------------------------------------------------------------------------------------------------------
50..............................................................              95               8              40
75..............................................................              95              30              66
95..............................................................              95             100             100
96..............................................................              95               5               9
173.............................................................             174               0               2
174.............................................................              95              50             120
175.............................................................             174               4               9
176.............................................................             174              93             101
177.............................................................             176               5               9
----------------------------------------------------------------------------------------------------------------
\1\ All ion abundances must be normalized to m/z 95, the nominal base peak, even though the ion abundance of m/z
  174 may be up to 120 percent that of m/z 95.

9.13 Routine CCV at the Start of a Sequence

    Run CCV before each sequence of analyses and after every tenth
sample to ensure that the previous multi-level calibration (see
Section 10.6.3) is still valid.
    9.13.1 The sample concentration used for the CCV should be near
the mid-point of the multi-level calibration range.
    9.13.2 Quantitation software must be updated with response
factors determined from the CCV standard. The percent deviation
between the initial calibration and the CCV for all compounds must
be within 30 percent.

9.14 CCV at the End of a Sequence

    Run another CCV after running each sequence of samples. The
initial CCV for a subsequent set of samples may be used as the final
CCV for a previous analytical sequence, provided the same analytical
method is used and the subsequent set of samples is analyzed
immediately (within 4 hours) after the last CCV.

9.15 Additional Verification

    Use a calibration check standard from a second, separate source
to verify the original calibration at least once every three months.

9.16 Integration Method

    Document the procedure used for integration of analytical data
including field samples, calibration standards and blanks.

9.17 QC Records

    Maintain all QC reports/records for each TD/GC/MS analytical
system used for application of this method. Routine quality control
requirements for this method are listed below and summarized in
Table 17.1.

10.0 Calibration and Standardization

    10.1 Calibrate the analytical system using standards covering
the range of analyte masses expected from field samples.
    10.2 Analytical results for field samples must fall within the
calibrated range of the analytical system to be valid.
    10.3 Calibration standard preparation must be fully traceable to
primary standards of mass and/or volume, and/or be confirmed using
an independent certified reference method.
    10.3.1 Preparation of calibration standard tubes from standard
atmospheres.
    <IP_ADDRESS> Subject to the requirements in Section 7.2.1, low-level
standard atmospheres may be introduced to clean, conditioned sorbent
tubes in order to produce calibration standards.
    <IP_ADDRESS> The standard atmosphere generator or system must be
capable of producing sufficient flow at a constant rate to allow the
required analyte mass to be introduced within a reasonable time
frame and without affecting the concentration of the standard
atmosphere itself.
    <IP_ADDRESS> The sampling manifold may be heated to minimize risk of
condensation but the temperature of the gas delivered to the sorbent
tubes may not exceed 100[emsp14][deg]F.
    <IP_ADDRESS> The flow rates passed through the tube should be in the
order of 50-100 mL/min and the volume of standard atmosphere sampled
from the manifold or chamber must not exceed the breakthrough volume
of the sorbent at the given temperature.
    10.4 Preparation of calibration standard tubes from concentrated
gas standards.
    10.4.1 If a suitable concentrated gas standard (see Section
7.2.2) can be obtained, follow the manufacturer's recommendations
relating to suitable storage conditions and product lifetime.
    10.4.2 Introduce precise 0.5 to 500.0 mL aliquots of the
standard to the sampling end of conditioned sorbent tubes in a 50-
100 mL/min flow of pure carrier gas.

    Note: This can be achieved by connecting the sampling end of the
tube to an unheated GC injector (see Section 6.6) and introducing
the aliquot of gas using a suitable gas syringe. Gas sample valves
could alternatively be used to meter the standard gas volume.

    10.4.3 Each sorbent tube should be left connected to the flow of
gas for 2 minutes after standard introduction. As soon as each
spiked tube is removed from the injection unit, seal it with long-
term storage caps and place it in an appropriate tube storage/
transportation container if it is not to be analyzed within 24
hours.
    10.5 Preparation of calibration standard tubes from liquid
standards.
    10.5.1 Suitable standards are described in Section 7.3.
    10.5.2 Introduce precise 0.5 to 2 [micro]l aliquots of liquid
standards to the sampling end of sorbent tubes in a flow (50-100 mL/
min) of carrier gas using a precision syringe and an unheated
injector (Section 6.5). The flow of gas should be sufficient to
completely vaporize the liquid standard.

    Note: If the analytes of interest are higher boiling than n-
decane, reproducible analyte transfer to the sorbent bed is
optimized by allowing the tip of the syringe to gently touch the
sorbent retaining gauze at the sampling end of the tube.

    10.5.3 Each sorbent tube is left connected to the flow of gas
for 5 minutes after liquid standard introduction.
    <IP_ADDRESS> As soon as each spiked tube is removed from the
injection unit, seal it with long-term storage caps and place it in
an appropriate tube storage container if it is not to be analyzed
within 24 hours.

    Note: In cases where it is possible to selectively purge the
solvent from the tube while all target analytes are quantitatively
retained, a larger 2 [micro]L injection may be made for optimum
accuracy. However, if the solvent cannot be selectively purged and
will be present during analysis, the injection volume should be as
small as possible (e.g., 0.5 [micro]L) to minimize solvent
interference.

    Note:  This standard preparation technique requires the entire
liquid plug including the tip volume be brought into the syringe
barrel. The volume in the barrel is recorded, the syringe is
inserted into the septum of the spiking apparatus. The liquid is
then quickly injected. Any remaining liquid in the syringe tip is
brought back into the syringe barrel. The volume in the barrel is
recorded and the amount spiked onto the tube is the difference
between the before spiking volume and the after spiking volume. A
bias occurs with this method when sample is drawn continuously up
into the syringe to the specified volume

and the calibration solution in the syringe tip is ignored.

    10.6 Preparation of calibration standard tubes from multiple
standards.
    10.6.1 If it is not possible to prepare one standard containing
all the compounds of interest (e.g., because of chemical reactivity
or the breadth of the volatility range), standard tubes can be
prepared from multiple gas or liquid standards.
    10.6.2 Follow the procedures described in Sections 10.4 and
10.5, respectively, for introducing each gas and/or liquid standard
to the tube and load those containing the highest boiling compounds
of interest first and the lightest species last.
    10.7 Additional requirements for preparation of calibration
tubes.
    10.7.1 Storage of Calibration Standard Tubes
    <IP_ADDRESS> Seal tubes with long-term storage caps immediately
after they have been disconnected from the standard loading manifold
or injection apparatus.
    <IP_ADDRESS> Calibration standard tubes may be stored for no longer
than 30 days and should be refrigerated if there is any risk of
chemical interaction or degradation. Audit standards (see section
9.11) are exempt from this criteria and may be stored for the shelf-
life specified on their certificates.
    10.8 Keep records for calibration standard tubes to include the
following:
    10.8.1 The stock number of any commercial liquid or gas
standards used.
    10.8.2 A chromatogram of the most recent blank for each tube
used as a calibration standard together with the associated
analytical conditions and date of cleaning.
    10.8.3 Date of standard loading.
    10.8.4 List of standard components, approximate masses and
associated confidence levels.
    10.8.5 Example analysis of an identical standard with associated
analytical conditions.
    10.8.6 A brief description of the method used for standard
preparation.
    10.8.7 The standard's expiration date.
    10.9 TD/GC/MS using standard tubes to calibrate system response.
    10.9.1 Verify that the TD/GC/MS analytical system meets the
instrument performance criteria given in Section 9.1.
    10.9.2 The prepared calibration standard tubes must be analyzed
using the analytical conditions applied to field samples (see
Section 11.0) and must be selected to ensure quantitative transfer
and adequate chromatographic resolution of target compounds,
surrogates, and internal standards in order to enable reliable
identification and quantitation of compounds of interest. The
analytical conditions should also be sufficiently stringent to
prevent buildup of higher boiling, non-target contaminants that may
be collected on the tubes during field monitoring.
    10.9.3 Calibration range. Each TD/GC/MS system must be
calibrated at five concentrations that span the monitoring range of
interest before being used for sample analysis. This initial multi-
level calibration determines instrument sensitivity under the
analytical conditions selected and the linearity of GC/MS response
for the target compounds. One of the calibration points must be
within a factor of five of the detection limit for the compounds of
interest.
    10.9.4 One of the calibration points from the initial
calibration curve must be at the same concentration as the daily CCV
standard (e.g., the mass collected when sampling air at typical
concentrations).
    10.9.5 Calibration frequency. Each GC/MS system must be
recalibrated with a full 5-point calibration curve following
corrective action (e.g., ion source cleaning or repair, column
replacement) or if the instrument fails the daily calibration
acceptance criteria.
    <IP_ADDRESS> CCV checks must be carried out on a regular routine
basis as described in Section 9.14.
    <IP_ADDRESS> Quantitation ions for the target compounds are shown in
Table 10.1. Use the primary ion unless interferences are present, in
which case you should use a secondary ion.

                                    Table 10.1--Clean Air Act Volatile Organic Compounds for Passive Sorbent Sampling
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Vapor                            Characteristic ion(s)
                       Compound                            CAS No.      BP  ([deg]C)      pressure         MW \b\     ----------------------------------
                                                                                (mmHg) \a\                        Primary         Secondary
--------------------------------------------------------------------------------------------------------------------------------------------------------
1,1-Dichloroethene...................................         75-35-4              32             500            96.9              61                 96
3-Chloropropene......................................        107-05-1            44.5             340            76.5              76         41, 39, 78
1,1,2-Trichloro-1,2,2-trifluoroethane-1,1-                    75-34-3            57.0             230              99              63    65, 83, 85, 98,
 Dichloroethane......................................                                                                                100
1,2-Dichloroethane...................................        107-06-2            83.5            61.5              99              62                 98
1,1,1-Trichloroethane................................         71-55-6            74.1             100           133.4              97             99, 61
Benzene..............................................         71-43-2            80.1            76.0              78              78  .................
Carbon tetrachloride.................................         56-23-5            76.7            90.0           153.8             117                119
1,2-Dichloropropane..................................         78-87-5            97.0            42.0             113              63                112
Trichloroethene......................................         79-01-6            87.0            20.0           131.4              95       97, 130, 132
1,1,2-Trichloroethane................................         79-00-5             114            19.0           133.4              83             97, 85
Toluene..............................................        108-88-3             111            22.0              92              92                 91
Tetrachloroethene....................................        127-18-4             121            14.0           165.8             164      129, 131, 166
Chlorobenzene........................................        108-90-7             132             8.8           112.6             112            77, 114
Ethylbenzene.........................................        100-41-4             136             7.0             106              91                106
m,p-Xylene...........................................  108-38-3, 106-             138             6.5           106.2             106                 91
                                                                 42-3
Styrene..............................................        100-42-5             145             6.6             104             104                 78
o-Xylene.............................................         95-47-6             144             5.0           106.2             106                 91
p-Dichlorobenzene....................................        106-46-7             173            0.60             147             146           111, 148
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Pressure in millimeters of mercury.
\b\ Molecular weight.

11.0 Analytical Procedure

11.1 Preparation for Sample Analysis

    11.1.1 Each sequence of analyses must be ordered as follows:
    <IP_ADDRESS> CCV.
    <IP_ADDRESS> A laboratory blank.
    <IP_ADDRESS> Field blank.
    <IP_ADDRESS> Sample(s).
    <IP_ADDRESS> Field blank.
    <IP_ADDRESS> CCV after 10 field samples.
    <IP_ADDRESS> CCV at the end of the sample batch.

11.2 Pre-desorption System Checks and Procedures

    11.2.1 Ensure all sample tubes and field blanks are at ambient
temperature before removing them from the storage container.
    11.2.2 If using an automated TD/GC/MS analyzer, remove the long-
term storage caps from the tubes, replace them with appropriate
analytical caps, and load them into the system in the sequence
described in Section 11.1. Alternatively, if using a manual system,
uncap and analyze each tube, one at a time, in the sequence
described in Section 11.1.
    11.2.3 The following thermal desorption system integrity checks
and procedures are required before each tube is analyzed.

    Note:  Commercial thermal desorbers should implement these steps
automatically.

    <IP_ADDRESS> Tube leak test: Each tube must be leak tested as soon
as it is loaded into the carrier gas flow path before analysis to
ensure data integrity.
    <IP_ADDRESS> Conduct the leak test at the GC carrier gas pressure,
without heat or gas flow applied. Tubes that fail the leak test
should not be analyzed, but should be resealed and stored intact. On
automated systems, the instrument should continue to leak test and
analyze subsequent tubes after a given tube has failed. Automated
systems must also store and record which tubes in a sequence have
failed the leak test. Information on failed tubes should be
downloaded with the batch of sequence information from the
analytical system.
    <IP_ADDRESS> Leak test the sample flow path. Leak check the sample
flow path of the thermal desorber before each analysis without heat
or gas flow applied to the sample tube. Stop the automatic sequence
of tube desorption and GC analysis if any leak is detected in the
main sample flow path. This process may be carried out as a separate
step or as part of Section <IP_ADDRESS>.

11.2.4 Optional Dry Purge

    <IP_ADDRESS> Tubes may be dry purged with a flow of pure dry gas
passing into the tube from the sampling end, to remove water vapor
and other very volatile interferents if required.

11.2.5 Internal Standard (IS) Addition

    <IP_ADDRESS> Use the internal standard addition function of the
automated thermal desorber (if available) to introduce a precise
aliquot of the internal standard to the sampling end of each tube
after the leak test and shortly before primary (tube) desorption).

    Note:  This step can be combined with dry purging the tube
(Section 11.2.4) if required.

    <IP_ADDRESS> If the analyzer does not have a facility for automatic
IS addition, gas or liquid internal standard can be manually
introduced to the sampling end of tubes in a flow of carrier gas
using the types of procedure described in Sections 10.3 and 10.4,
respectively.
    11.2.6 Pre-purge. Each tube should be purged to vent with
carrier gas flowing in the desorption direction (i.e., flowing into
the tube from the non-sampling end) to remove oxygen before heat is
applied. This is to prevent analyte and sorbent oxidation and to
prevent deterioration of key analyzer components such as the GC
column and mass spectrometer (if applicable). A series of schematics
illustrating these steps is presented in Figures 17.2 and 17.3.

11.3 Analytical Procedure

11.3.1 Steps Required for Thermal Desorption

    <IP_ADDRESS> Ensure that the pressure and purity of purge and
carrier gases supplying the TD/GC/MS system, meet manufacturer
specifications and the requirements of this method.
    <IP_ADDRESS> Ensure also that the analytical method selected meets
the QC requirements of this method (Section 9) and that all the
analytical parameters are at set point.
    <IP_ADDRESS> Conduct predesorption system checks (see Section 11.2).
    <IP_ADDRESS> Desorb the sorbent tube under conditions demonstrated
to achieve >95 percent recovery of target compounds (see Section
9.5.2).

    Note:  Typical tube desorption conditions range from 280-350
[deg]C for 5-15 minutes with a carrier gas flow of 30-100 mL/min
passing through the tube from the non-sampling end such that
analytes are flushed out of the tube from the sampling end. Desorbed
VOCs are concentrated (refocused) on a secondary, cooled sorbent
trap integrated into the analytical equipment (see Figure 17.4). The
focusing trap is typically maintained at a temperature between -30
and +30 [deg]C during focusing. Selection of hydrophobic sorbents
for focusing and setting a trapping temperature of +25 to 27 [deg]C
aid analysis of humid samples because these settings allow selective
elimination of any residual water from the system, prior to GC/MS
analysis.

    Note:  The transfer of analytes from the tube to the focusing
trap during primary (tube) desorption can be carried out splitless
or under controlled split conditions (see Figure 17.4) depending on
the masses of target compounds sampled and the requirements of the
system--sensitivity, required calibration range, column overload
limitations, etc. Instrument controlled sample splits must be
demonstrated by showing the reproducibility using calibration
standards. Field and laboratory blank samples must be analyzed at
the same split as the lowest calibration standard. During secondary
(trap) desorption the focusing trap is heated rapidly (typically at
rates >40 [deg]C/s) with inert (carrier) gas flowing through the
trap (3-100 mL/min) in the reverse direction to that used during
focusing.

    <IP_ADDRESS> The split conditions selected for optimum field sample
analysis must also be demonstrated on representative standards.

    Note:  Typical trap desorption temperatures are in the range
250-360 [deg]C, with a ``hold'' time of 1-3 minutes at the highest
temperature. Trap desorption automatically triggers the start of GC
analysis. The trap desorption can also be carried out under
splitless conditions (i.e., with everything desorbed from the trap
being transferred to the analytical column and GC detector) or, more
commonly, under controlled split conditions (see Figure 17.4). The
selected split ratio depends on the masses of target compounds
sampled and the requirements of the system--sensitivity, required
calibration range, column overload limitations, etc. If a split is
selected during both primary (trap) desorption and secondary (trap)
desorption, the overall split ratio is the product of the two. Such
`double' split capability gives optimum flexibility for
accommodating concentrated samples as well as trace-level samples on
the TD/GC/MS analytical system. High resolution capillary columns
and most GC/MS detectors tend to work best with approximately 20-200
ng per compound per tube to avoid saturation. The overall split
ratio must be adjusted such that, when it is applied to the sample
mass that is expected to be collected during field monitoring, the
amount reaching the column will be attenuated to fall within this
range. As a rule of thumb this means that ~20 ng samples will
require splitless or very low split analysis, ~2 [micro]g samples
will require a split ratio in the order of ~50:1 and 200 [micro]g
samples will require a double split method with an overall split
ratio in the order of 2,000:1.

    <IP_ADDRESS> Analyzed tubes must be resealed with long-term storage
caps immediately after analysis (manual systems) or after completion
of a sequence (automated systems). This prevents contamination,
minimizing the extent of tube reconditioning required before
subsequent reuse.

11.3.2 GC/MS Analytical Procedure