Recently we had the opportunity to collaborate with a major lab in Germany that specializes in analyzing urines for drugs of abuse. The lead pharmacist there showed me her lab and explained in detail what she analyzes every day, which instrumentation she uses for analyzing medication, and how she collaborates with forensic institutes to analyze drugs of abuse.
We looked into the details of the chromatograms and she explained to me how she was able to find evidence of drug use in the urine samples, including all metabolites and some new designer drugs. To perform such analysis there are certain elements that are absolutely key to a successful approach.
When a urine sample arrives in the lab, the lab performs immunological analysis first to define which class of drugs was being used. The urine samples are subsequently extracted using Solid Phase Extraction, or SPE, to perform both a clean-up and a concentration factor. The extract is subsequently analyzed on an ISQ™ 7000 Single Quadrupole GC-MS System where we can screen and securely identify benzodiazepines, opiates, synthetic cannabinoids, synthetic opioids, neuroleptics, etc.
It is quite important to be able to detect metabolites of the drugs at very low levels. Some of these compounds, especially the new synthetic drugs, are extremely potent and are often ingested in very low amounts. The GC-MS system needs to be very sensitive to be able to detect these compounds. Learn more about this here.
Another consideration is the matrix and the impact it might have on the system. Although Solid Phase Extraction (SPE) is performed there is a still a very high amount of matrix offered to the system and the complete system needs to be rugged enough to handle a significant amount of urine injections.
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The next thing that is paramount is to be able to correctly identify the drugs. As one might imagine the chromatography is very complex in a matrix like urine. So a combination of good spectral cleanup with deconvolution and libraries are needed. There are sources of libraries for drugs-of-abuse freely available, such as Scientific Working Group for the Analysis of Seized Drugs (SWGDRUG) and the Cayman spectral libraries. Both are very regularly updated. Learn more here.
We can also tell a lot about the lifestyle of a subject in general. The pharmacist pointed out some typical compounds that are found in the urines of smokers, and of course as you can imagine, nicotine is one of those markers.
The thing that I found most surprising is that it is also possible to determine if chocolate has been eaten or not. In almost all of the German urine samples we found theobromine, and this is a marker of chocolate consumption. What was even more surprising to me, we could even tell if the consumption was massive or not. To be fair on our friends, the Germans: it was indeed around Eastertime and I have the feeling we would struggle to find any theobromine-free urines across Europe in that particular time of the year.
So yes, we can tell if you are a choc-a-holic or not!