A simple, quick and non-destructive approach for sampling drugs of abuse in tablets and blotter for qualitative analysis by paper spray mass spectrometry

This study presents the development of a simple, fast, and inexpensive approach for the direct analysis of new psychoactive substances (NPS) in seized tablets and blotter paper, with improved sample preservation and increased analytical frequency. Paper triangles were gently rubbed against the surface of the samples containing synthetic drugs and then subjected to analysis by paper spray ionization mass spectrometry (PS-MS). Seized samples containing lysergic acid diethylamide (LSD) and several other substances from the classes of amphetamines, N-benzyl-substituted phenethylamines, synthetic cathinones, and synthetic cannabinoids, were analysed. Three types of paper were tested (filter paper, blotter paper, and synthetic paper) and several combinations of spray solvents were studied for the optimization. All samples were weighed and photographed before and after sequences of analysis in order to attest to the sample preservation. The results revealed that the approach is excellent for sample preservation, with less than 5% of mass loss even after 27 consecutive analyses. Moreover, no significant signal decreases were observed in mass spectrometry (MS) even after the experiments. It was possible to unequivocally identify illicit substances from seized samples (pills and blotter paper). By overcoming the solubilization and wet extraction process used for sample preparation, the waste was restricted to a volume of only 10 μL of solvent for the PS-MS analysis. The main advantage of our approach over existing methods is the sample preparation, which is simple and quick since the samples are just rubbed against the PS paper. This brings enormous benefits in terms of analytical frequency, economy of time and low consumption of solvents. Another important point is that the sample can remain intact for further analysis, which is crucial in forensic analysis.