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Cocaine 'profile' helps track drug trade

war on drugs

A Venezuelan soldier stands guard over bags of seized cocaine (Image: Reuters/Howard Yanes)

Profiling illegally imported cocaine to pinpoint its country of origin is helping police identify drug syndicates and trafficking routes, an Australian chemist says.

Michael Collins, director of the Australian Forensic Drug Laboratory at the National Measurement Institute in Sydney, says cocaine has a chemical profile that can reveal its geographical origin, along with the conditions under which it was grown and the way it was processed.

Collins and co-author Hilton Swan will tell this week's Metrology Society of Australia's national conference in Adelaide that four main chemical 'signatures' are the key to profiling cocaine.

These are: two groups of organic compounds, the tropane and truxilline alkaloids; the solvents absorbed during processing; and the isotope ratios of carbon and nitrogen.

"None of these signatures on their own tell you anything," Collins says. "It is only when you put them in combination that they reveal the location."

Collins says scientists can use profiling to locate the origin of cocaine because only two coca plant species and two variants of those species produce significant amounts of the drug.

And he says the main cocaine-producing countries of Bolivia, Colombia and Peru favour different species.

He says for example, the concentration of truxilline is a very good indicator of whether the cocaine is from Peru or Colombia.

Peruvian cocaine contains on average less than 5% truxilline while cocaine from southwest Colombia averages around 15%, Collins says.

Soil type

The isotopes ratio of nitrogen-15 to nitrogen-14, which is affected by the soil type in which the coca plant is grown, shows where on the Andean ridge the coca plant originates. The ratio tends to get lower the further south the plant is grown.

Collins says the ratio of isotopes carbon-13 to carbon-12 is a constant for any given region.

"But one thing that affects carbon-12 dramatically is altitude as it stresses the plant and affects how it [takes] in carbon dioxide," Collins says.

"As we travel from Colombia to Bolivia you are dropping height considerably and you notice the ratio becomes more negative."

He says traces of the solvents used in processing that remain in the cocaine are good indicators of where the drug was processed because different solvents are used in different countries.

Drug cartels

"To process coca into cocaine base then into cocaine hydrochloride, drug cartels use various solvents," Collins says, "and they stick to the same solvents."

This information is important because it helps drug intelligence officers trace the transport route of cocaine.

Collins says the cocaine profiling program in Australia started about 18 months ago and more than 1000 seized samples have been analysed. This data is now being compiled into a database that will be used by the Australian Federal Police.

Information about the source of the drug and where and how it was processed can help identify syndicates and establish transport routes, he says.

Collins says central to the development of the database was the cooperation of the US Drug Enforcement Agency, which provided a check sample of cocaine.

This was then used to create an Australian standard, against which all seized samples could be analysed.

Tags: environment, agricultural-crops, chemistry, computers-and-technology