The aim of this thesis was to develop different analytical approaches dedicated to the analysis of new psychoactive substances in different biological matrices (blood, urine and hair). The first approach is based on untargeted screening by biochip array technology chemiluminescence assay (BAT) and liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS), and the second corresponds to a targeted screening by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). These methods were then applied in observational studies to assess the consumption of NPS in high-risk populations (overdose, drug abuse, drug-facilitated crimes, men who have sex with men MSM) in clinical and forensic settings. The last part of the thesis was devoted to the development of new tools for LC-HRMS data processing which made it possible to study the metabolism of different NPS in vitro on human liver microsomes (HLM) and in vivo in biological samples from drug users. This approach has enabled the creation of HRMS spectral library containing over 200 metabolites, some of which have been suggested as relevant markers of NPS exposure.

This work has resulted on 10 scientific publications and allowed to initiate many multidisciplinary collaborations.