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Abstract :
[en] Background and aim: Various seized materials consisting of powders, tablets, cannabis and related paraphernalia were submitted to the laboratory for identification in order to confirm drug trafficking by a woman in her thirties. Notably, a combination of vials with a pharmaceutic appearance, one containing a white powder and the other a liquid was also seized.
Methods: Samples were submitted to a chromatographic analysis by high-performance liquid chromatography with a diode array detector (HPLC-DAD). A second analysis was performed using an ultra-high-performance liquid chromatograph coupled to a high-resolution mass spectrometer (UHPLC-TOF-MS).
Results: Most of the samples were easily quantified as cocaine, MDMA, amphetamine or ketamine.
Additionally, clephedrone, a new psychoactive substance, was also identified in domino-shaped tablets. The main difficulty lay in identifying the vials with a pharmaceutical appearance.
Despite significant peak with retention time of 11.4 minutes and UV spectra showing maxima at 200 and 280 nm, no match was found in the library through HPLC-DAD analysis. Fortunately, the vials were labeled as “Melanotan” which proved very helpful, even though the UV spectrum was not available in the literature or classical databases. The acquisition of the reference standard allowed us to confirm the identification with HPLC-DAD and TOF-MS. Melanotan is not approved on the international drug market due to safety concerns. It is used illegally for weight loss, libido stimulation, and more importantly tanning. In fact, the drug has earned the nickname "Barbie drug" due to its popularity as a tanning agent.
Mass spectrometric analysis of melanotan was challenging, as melanotan is a small peptide with a molecular weight of 1024 Da, which is significantly heavier than most of classical drugs of abuse and medicines that the laboratory usually handles. As a result, mass spectrometer's parameters can be limited to detect masses up to 1000 Da. Additionally, melanotan is also multi-charged which is also unusual for compounds typically targeted in our daily work.
Conclusion: Analytic confirmation of melanotan involves a number of traps, due to its peptide nature.
Proteins analysis involves specific techniques and expertise and there are several pitfalls to be aware of.
