Toxicological screening of basic drugs in whole blood using UPLC-TOF-MS

Ultra performance liquid chromatography (UPLC) coupled with time-of-flight (TOF) mass spectrometry (MS) was established for toxicological screening of basic drugs in whole blood and tested on authentic samples. Whole blood samples (0.2 ml) were extracted using a Gilson apparatus equipped with Bond Elut Certify columns. Screening was performed for 175 compounds (psychotropic, cardiovascular, designer, and abused drugs). The drugs were separated in 15 min using a UPLC system (Waters ACQUITY BEH C18, 1.7 µm, 2.1 mm × 100 mm column) coupled to an LCT Premier XE (Waters) instrument. Data were processed by ChromaLynx XS using identification criteria of ± 0.2 min retention time, and ± 5 mDa mass tolerance. Whole blood was spiked with the 175 compounds in concentrations from 5-100 µg/kg to assess approximately the lowest concentrations that could be identified. This method was further applied to 119 samples from forensic investigations, leading to 302 hits, of which 291 (96%) were subsequently verified, in concentrations exceeding the lower limit of quantification (LLOQ), by a liquid chromatography (LC)-MS/MS confirmation method. In conclusion, this UPLC-TOF-MS method is a useful and effective screening method for basic drugs in whole blood.