Postmortem redistribution of methamphetamine and amphetamine in blood specimens from various blood vessels and in the specimens from pericardial fluid, bile, stomach contents and various solid tissues collected from a human cadaver

We recently encountered an autopsy case in which methamphetamine (MA) was involved. The postmortem interval was estimated to be as long as 6–7 days. We collected the blood specimens from 9 locations of the heart and blood vessels, and specimens from pericardial fluid, bile, stomach contents and 9 solid tissues (in total 21 specimens), which were subjected to analysis of MA and the metabolite amphetamine by liquid chromatography–tandem mass spectrometry after a modified QuEChERS extraction. The highest concentration of MA was found for the stomach contents, suggesting the oral ingestion of MA. Among the blood specimens, their MA concentrations varied from 268 to 911 ng/mL. The concentration of MA in the left heart blood was higher than that in the right heart blood. In spite of this, the MA concentration in the pulmonary vein was much lower than that in the left heart blood. The comparison of MA concentrations in venous blood vessels showed that MA concentration was highest in the vena cava, followed by the iliac vein, and was lowest in the femoral vein, suggesting that MA concentration is decreased by diffusion across the thin walls of venous blood vessels during the postmortem interval. The partial loss of a xenobiotic by diffusion via the thin wall of the femoral vein should be taken into consideration especially when the postmortem interval is relatively long.