Determination of multiple psychostimulants and antipsychotics in postmortem dried blood spot samples by liquid chromatography-tandem mass spectrometry.

When dealing with psychostimulant and antipsychotic poisoning deaths in forensic practice, detection and accurate quantification of the causative drug are essential for a definitive diagnosis. If post-mortem changes have resulted in the presence of various adulterants in the blood, commercially available simple screening kits may produce false positives. In this study, we focused on applying dried blood spot (DBS) samples to develop a simple and accurate method for forensic toxicological analysis of drugs of interest in poisoning deaths. To test our novel analytical method we used liquid chromatography coupled with electrospray ionization-tandem mass spectrometry to quantify two psychostimulants (amphetamine, methamphetamine) and eight antipsychotics (chlorpromazine, haloperidol, levomepromazine, aripiprazole, clozapine, quetiapine, risperidone, and paliperidone) in cadaveric DBS samples. The linearities of the calibration curves were good in the concentration range of 0.05-1.0 μg/mL. The method allowed for repeatable and accurate quantification of the 10 target drugs with intra- and inter-assay coefficients of variation of below 10.6 % and 12.4 %, respectively. In addition, the concentrations of all drugs stored at -80 °C in DBSs remained almost stable for at least 2 weeks. Comparison with our general practice method (known as QuEChERS) showed good positive correlations of the quantifiable concentrations of all drugs. In addition, for all drugs, the concentrations obtained by the DBS method were almost well coincident with those obtained by the QuEChERS method.