Simultaneous screening and quantification of 52 common pharmaceuticals and drugs of abuse in hair using UPLC-TOF-MS

Abstract

An UPLC-TOF-MS method for simultaneous screening and quantification of 52 drugs in hair was developed and validated. The selected drugs represent the most common classes of pharmaceuticals and drugs of abuse such as amphetamines, analgesics, antidepressants, antipsychotics, benzodiazepines, cocaine, ketamine and opioids. Hair samples were extracted with methanol:acetonitrile:ammonium formate (2 mM, 8% acetonitrile, pH 5.3) overnight at 37 degrees C. The target drugs were separated and quantified using a Waters ACQUITY UPLC coupled to a Waters Micromass LCT Premier XE Time-of-Flight mass spectrometer. Total chromatographic run time was 17min. The data were treated with the MassLynx software ChromaLynx XS and QuanLynx for automated identification and quantification, respectively. The limits of detection ranged from 0.01 to 0.10 ng/mg using a 10-mg hair sample and the limit of quantification was 0.05 ng/mg for 87% of the analytes. A good linear behaviour was achieved for most of the analytes in the range from LOQ to 10 or 25 ng/mg except for the amphetamines. The method showed an acceptable precision and trueness, since the obtained CV and BIAS values were <or=25% for 81% of the analytes. The extraction recoveries for 92% of the analytes ranged between 84 and 106% and the extraction recoveries for all analytes were better than 60%. The method was applied to 15 autopsy hair samples from forensic investigations showing a wide abuse pattern of many pharmaceuticals and drugs of abuse within a period of less than three months. The present study demonstrated that the combination of accurate mass and retention time can provide good selectivity, which demonstrates that the TOF instrument is adequate for both screening and quantification purposes. Furthermore, it was shown that screening with the ChromaLynx XS software is less sensitive and selective for some analytes than the QuanLynx software, especially in low concentrations.