Recent Trends in Analytical Methods to Determine New Psychoactive Substances in Hair.
BACKGROUND
New Psychoactive Substances (NPS) belong to several chemical classes, including phenethylamines, piperazines, synthetic cathinones and synthetic cannabinoids. Development and validation of analytical methods for the determination of NPS both in traditional and alternative matrices is of crucial importance to study drug metabolism and to associate consumption to clinical outcomes and eventual intoxication symptoms. Among different biological matrices, hair is the one with the widest time window to investigate drug-related history and demonstrate past intake.


METHODS
The aim of this paper was to overview the trends of the rapidly evolving analytical methods for the determination of NPS in hair and the usefulness of these methods when applied to real cases. A number of rapid and sensitive methods for the determination of NPS in hair matrix has been recently published, most of them using liquid chromatography coupled to mass spectrometry. Hair digestion and subsequent solid phase extraction or liquid-liquid extraction were described as well as extraction in organic solvents. For most of the methods limits of quantification at picogram per milligram hair were obtained.


RESULTS
The measured concentrations for most of the NPS in real samples were in the range of picograms of drug per milligram of hair. Interpretation of the results and lack of cut-off values for the discrimination between chronic consumption and occasional use or external contamination are still challenging.


CONCLUSIONS
Methods for the determination of NPS in hair are continually emerging to include as many NPS as possible due to the great demand for their detection.
Unit of Forensic Toxicology (UoFT), Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, Viale Regina Elena 336 (00185) Rome. Italy.
Chrystalla
C
Kyriakou
Department of Therapeutic Research and Medicines Evaluation, Istituto Superiore di Sanita, Viale Regina Elena 299, 00161, Rome. Italy.
Manuela
M
Pellegrini
Department of Pediatrics, Group of Research on Childhood and Environment (GRIE), Institute Hospital del Mar of Medical Research (IMIM), Hospital del Mar, 08003 Barcelona, Spain. Spain.
Oscar
O
García-Algar
Unit of Forensic Toxicology (UoFT), Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, Viale Regina Elena 336 (00185) Rome. Italy.
Enrico
E
Marinelli
Unit of Forensic Toxicology (UoFT), Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, Viale Regina Elena 336 (00185) Rome. Italy.
Simona
S
Zaami
D002623:Chemistry Techniques, Analytical / Q000379:methods* / Q000639:trends*; D006197:Hair / Q000737:chemistry*; D006801:Humans; D011619:Psychotropic Drugs / Q000032:analysis*
D011619:Psychotropic Drugs
New psychoactive substances; analytical methods; hair; phenethylamines; piperazines; synthetic cannabinoids; synthetic cathinones