Development and validation of a UHPLC-MS/MS method for the simultaneous determination of 100 drugs in human hair

This study presents the development and validation of a one-step extraction method coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the simultaneous analysis of 100 compounds in human hair. Specifically, the method can detect a broad range of drugs in human hair, including analgesics, antidepressants, antipsychotics, benzodiazepines, classic drugs of abuse (DOA) and novel psychoactive substances (NPS). The drugs were extracted from 20 mg of washed hair by incubation for 3 h in a mixture of 1 mL of 0.1 M HCl in methanol. Analytical performance was evaluated in terms of linearity, sensitivity, accuracy, precision, matrix effects and recovery. The developed method demonstrated high sensitivity (the limits of detection (LOD) ranged from 1.25 to 150 pg/mg and the quantitation limit (LOQ) ranged from 3.75 to 450 pg/mg), accuracy and precision were within acceptable limits. The matrix effect expressed as ion suppression/enhancement of each analyte was in the range ± 25% for all analytes. Post-preparative stability of analytes was higher than 85%, while no carryover between runs was observed. Application to authentic hair samples confirmed its potential to detect a wide range of drugs and metabolites and to reveal patterns of drug use. Overall, the method offers a practical and efficient tool for comprehensive hair analysis, well suited for routine forensic and clinical toxicology in the context of increasing polydrug exposure.