 The use of passive sampling devices, such as Chemcatcher® or polar organic chemical integrative sampler (POCIS), have a number of advantages over the use of spot or bottle sampling for monitoring pollutants in the aquatic environment.The latter technique gives only an instantaneous concentration of the pollutant as the specific time of sampling.Passive samplers, depending on their mode of use, can give either the TWA or equilibrium concentration of the pollutant over the deployment period.