Combination of pressurized liquid extraction with dispersive liquid liquid micro extraction for the determination of sixty drugs of abuse in hair

The increasing phenomenon of drug addiction and the introduction of New Psychoactive Substances (NPS) have led to a progressive growth of research in the field of forensic analytical toxicology, with the need to develop modern and faster analytical procedures. Hair testing has gained increasing attention and recognition as a complement to blood and urine analysis, since it is a unique material for the retrospective detection of drugs, due to its large detection window. In this paper, a multiclass method for the simultaneous extraction, identification and quantification of sixty drugs of abuse belonging to different chemical classes in hair is proposed. This method can provide a valid, fast, simple and low-cost alternative to common tests; at the same time, it provides quantitative results, to concurrently confirm the assumption of one or more illicit substances. Both the decontamination step and the extraction of the analytes from the inner core of the hair were carried out by means of pressurized liquid extraction (PLE) while the clean-up was performed by dispersive liquid/liquid microextraction (dLLME), giving the great advantage of a high enrichment factor. The selected chromatographic conditions allowed a satisfying separation of the 60 analytes in 14 min, while the detection was conducted with a high-resolution mass spectrometer with Orbitrap technology. This multiclass method was suitable for analytes with different chemical characteristics allowing to reduce time and cost of analysis, organic solvent volume and the amount of sample required for analysis. The whole method was fully validated as confirmatory method following SWGTOX guidelines.