Simultaneous determination of 5 psychotropic drugs of various types in an autopsy case of acute multiple drug poisoning

Abstract

We attempted the simultaneous determination of 5 drugs, mirtazapine, sertraline, chlorpromazine, amoxapine and zolpidem, detected in a gas chromatography–mass spectrometry screening test in an autopsy case. The solid-phase extraction of the analytes from biological samples was achieved using Oasis®HLB cartridges (Waters, Milford, MA, USA). Gas chromatography was performed on a HP-5MS fused silica capillary column (30m×0.25mm i.d., 0.25μm film thickness, Agilent Technologies). The mass spectrometer was operated with an electron energy of 70eV in electron impact mode. The qualitative and quantitative analyses were performed in full-scan mode and the selected ion monitoring mode, respectively. The total ion chromatogram showed good separation of these drugs. Linear graphs were obtained with good correlation coefficients for these drugs from 0.001 to 2.0μg/mL (r2=0.9909–0.9986) using imipramine-d6 as an internal standard. The recoveries of these drugs were found to be 62.8–88.0% in spiked whole blood. Mirtazapine, sertraline, chlorpromazine, amoxapine and zolpidem were found in post-mortem samples of the deceased at concentrations of 2.67, 0.07, 0.25, 0.32 and 0.68μg/mL, respectively. The concentration of mirtazapine was within the lethal level and those of amoxapine and zolpidem were within the toxic level. We diagnosed that the cause of death was acute multiple drug poisoning. The simple and practical procedure used in this study is useful for the simultaneous determination of psychotropic drugs of various types in post-mortem biological samples.