The analysis of psychoactive substances in hair is of great importance for both clinical and forensic toxicologists since it allows one to evaluate past and continuative exposure to xenobiotics. In particular, a new challenge is represented by new psychoactive substances: Among this new class of drugs of abuse, synthetic cathinone and phenethylamine derivatives are often detected in biological samples. Hence, there is a growing need to develop new analytical procedures or improve old ones in order to conduct evaluations of these emerging substances. This study is a systematic review of all the instrumental and experimental data available in the literature. A total of 32 articles were included in the review. Acidic solvents proved to be the most reliable solutions for extraction. Gas chromatography and liquid chromatography coupled to tandem mass spectrometric and high-resolution mass spectrometric systems represent the majority of the involved instrumental techniques. Sensitivity must be maintained at the pg/mg level to detect any occurrences up to occasional consumption. In total, 23 out of 32 articles reported real positive samples. The most frequently detected substance in hair was mephedrone, followed by butylone, methylone, MDPV, and α-pyrrolidinophenone-type substances.
Keywords: NPS; hair analysis; phenylethylamine and derivatives; synthetic cathinones.