LC–MS-MS Determination of 88 Psychotropic Drugs in 1,865 Hair Samples from Addicts in Drug Abstinence

Abstract

Abstract The emergence of novel drugs and the continuous expansion of the scope of the types of drugs under control have greatly increased requests for screening of a range of drugs in hair. Here, a multi-analyte method for the detection and quantification of 88 psychotropic drugs in the hair of addicts in drug abstinence was developed and fully validated using liquid chromatography–tandem mass spectrometry (LC–MS-MS). Hair samples (25 mg) were washed, cut into pieces, cryogenically ground and extracted in methanol. The extracted analytes were separated on an Allure PFP Propyl column (100 × 2.1 mm, 5 mm inside diameter, Restek, USA) and analyzed by LC–MS-MS in multiple reaction monitoring modes. The limits of detection and the limits of quantification ranged from 0.1 to 20 pg/mg and 0.2 to 50 pg/mg, respectively. The intra- and inter-assay precisions (relative standard deviation (RSD)) of all analyses ranged from 0.9% to 14.9% and 1.9% to 15.9%, respectively. Accuracy values were 100 ± 20%. The extraction recovery of quality control samples ranged from 50.9% to 99.6% for all analytes. The matrix effects for all analytes ranged from 46.8% to 99.7%. The method was successfully used to analyze 1,865 hair samples from addicts in drug rehabilitation at their own communities. Among the samples, 129 cases were positive; the majority of positive cases were from males (78.29%), 92.25% of whom were >35 years old. Traditional drugs, like methamphetamine and opioids, accounted for most positive cases, and 27 of the abstinence cases with a use history of methamphetamine were still positive. In addition to abused drugs, like methamphetamine, morphine and cocaine, the sedative-hypnotic and psychotherapeutic drugs, including clonazepam, alprazolam, estazolam, zolpidem and quetiapine, were detected in 26% of the hair samples, suggesting that these addicts may have insomnia and mental problems such as depression and psychosis, probably due to the long-term effects of drugs and withdrawal reactions. Three synthetic cannabinoids were also detected in four (2.7%) cases. A total of 37 cases were positive for methadone, tramadol and dextromethorphan, reflecting a new trend of alternative drug use when traditional drugs were not easy to obtain during the coronavirus disease 2019 outbreak.