This fascination with science has not only lead to my current position as a PhD student in Sydney, but has also given me the opportunity to work with high school students, and present forensic science and chemistry workshops for those that are interested. The look of excitement and fascination on the faces of the students bestows a remarkable feeling, and I am glad to be able to have a chance to ignite and pass on a passion for science that a humble chemistry set ignited in me all those years ago.
The research that I am currently working on pertains to urine testing for recreational substances, specifically, cannabis use. Though urine testing for a range of licit and illicit substances is well established, in recent years there has been an increasing problem with the use of adulterants to chemically alter urine samples in order to obtain a false negative. Currently, I am exploring a range of oxidising agents and their effect on urine samples that have been spiked with a key metabolite of delta-9-tetrahydrocannabinol (THC), 11-nor-9-carboxy THC (THC-COOH).
The key issue with the use of adulterants, in particular oxidising adulterants, is that they react with the metabolites present in a positive urine sample. These reactions render common methods to test urine samples ineffective. From immunoassays such as ELISA, to mass spectrometric techniques, these samples fly under the radar, as it were, for subtle changes to the structure of the metabolites of interest result in novel compounds that are not associated with a positive urine sample. Therefore, it has been the goal of my research to react THC-COOH with a range of oxidising agents, and to explore whether novel reaction products are formed, and if so, whether they are stable and suitable for incorporation into current testing procedures.
Urine adulteration has therefore become an increasing problem for law enforcement agencies. This has been compounded by the availability of a number of oxidising agents, able to be bought online or at your local supermarket. On that note, from the fantastic Adult Swim cartoon Metalocalypse, some insight on this matter:
- Pickles: Dudes, we party too hard, so our bodies are in terrible shape. We gotta trick the doctor by making it seem like we're in really good shape. And there's only one way to do that. Bleach. [holds up a jug of bleach] Here, drink this Murderface. [hands it to Murderface]
- Skwisgaar: Uhh, maybe this ams a stupid question, buts, why don'ts we just pours bleach into our cups of...urines?
- Pickles: [looking angry at the suggestion] No! Drink the bleach!
- Nathan: Bleach is healthy. It's mostly water. And we are mostly water. Therefore, we are bleach.
As a sidenote, please don't drink bleach. Pretty please?
Results have been promising to date. A number of viable oxidising agents have been selected, including betadine, alkaline hypochlorite (bleach), potassium/sodium nitrite, and pyridinium chlorochromate. As THC-COOH is quite prone to oxidation, a number of viable intermediates and products have been isolated, and are in the process of being analysed. For the oxidising agents containing halogens, it appears that electrophilic aromatic substitution (EAS) produces mono-halogen derivatives of THC-COOH as intermediates, with the di-halogen (di-chloro and di-iodo) THC-COOH derivatives representing the ultimate products. For nitrite-based reactions, an unstable nitroso-containing derivative forms, which undergoes further reaction to produce a stable nitro-THC-COOH compound.
Well, that covers who I am and what I do. As for this blog, well, I intend to comment on the perception of science, chemistry and drugs within society, and to discuss fascinating articles and the like.
So, thank you for reading this far. I truly hope that you will find my writings and ramblings fascinating. With kindest regards,