Multi-residue analysis of sedative drugs in human plasma by ultra-high performance liquid chromatography tandem mass spectrometry

Background: Sedative drugs are often used for the treatment of depression, anxiety and insomnia and they are involved in many forensic cases. This work established a method for the simultaneous determination of multi groups of sedative drugs (benzodiazepines, barbitals, phenothiazines, tricyclic antidepressant and butyrophenone) in human plasma for forensic analysis. A large number of sedative drugs with forensic interest can be analyzed in a short time with lower limits of quantification by combination of SPE extraction and ultra performance liquid chromatography-tandem mass spectrometry. Methods: Sample preparation consisted of extraction of the plasma by hydrochloric acid solution and further purified by SLW solid phase extraction column. Results: The method was fully validated to cover large concentration ranges of 50-1000 mu g/L for 5 Barbital drugs, while 1.0-50 mu g/L for the other 14 sedative drugs. The average recoveries of the drugs spiked at three levels ranged from 65.3% to 114.3% with the relative standard deviation between 1.2% and 13.2%. The lowest limits of quantification (LLOQ) were 100 mu g/L for Barbital drugs and1.0 mu g/L for all the other 14 drugs. Conclusions: This validated method has been successfully used in emergency analysis of multi-residues of sedative drugs in plasma.