Homicide involving Aconitum tuberous root: LC-MS-MS analysis of Aconitum alkaloids and their hydrolysates in formalin-fixed tissues

We describe a homicide case involving Aconitum tuberous roots, in which formalin-fixed solid tissues were analyzed for diester-type Aconitum alkaloids and their hydrolysates by liquid chromatography-tandem mass spectrometry (LC-MS-MS). The specimens were taken from a cadaver 12 days after death, and preserved in formalin solution for 5 years. Polymer-based solid-phase extraction was employed for sample cleanup. This procedure allowed detection of 0.10 ng/g for each of the spiked alkaloids from the formalin-fixed liver by quadrupole LC-MS-MS, and 10 pg/g for benzoylaconine and benzoylmesaconine by ion-trap LC-MS-MS. Sub-parts-per-billion levels of benzoylaconine and benzoylmesaconine could be detected from the formalin-fixed liver, kidney, and lung specimens.