Novel extraction method using an ISOLUTE PLD+ protein and phospholipid removal column for liquid chromatography-tandem mass spectrometry analysis of 20 psychoactive drugs in postmortem whole blood samples

A novel sample extraction method using an ISOLUTE PLD+ protein and phospholipid removal column was developed for simultaneous quantification of 20 psychoactive drugs, including antidepressants, antipsychotics, sedative-hypnotics, and amphetamines, in postmortem whole blood samples by liquid chromatography-tandem mass spectrometry. The method showed improvement in extract cleanliness compared with traditional protein precipitation and the QuEChERS extraction method. The method was validated for all analytes; the calibration curves showed good linearity, with r² values exceeding 0.991. The intra- and interday accuracies and precisions were 87.6-117.5% and 1.0-18.6%, respectively. The recovery efficiencies were in the range of 64.6-96.8%. Matrix effects were observed in the range of 82.6-116.0%. All analytes were stable under different storage conditions. This method was successfully applied in postmortem forensic sample analysis to quantify psychoactive drugs. The method described in the current study will be useful for forensic toxicological investigations.