An evaluation of postmortem concentrations of Δ
Δ9-tetrahydrocannabinol (THC), the primary psychoactive component of cannabis, leads to impaired cognitive and psychomotor function resulting in an increased risk of fatal motor vehicle collisions and other traumas resulting in death. It is important to measure cannabinoids in postmortem cases to improve understanding of this growing public safety issue. However, postmortem concentrations of THC and its primary inactive metabolite, 11-nor-9-carboxy-tetrahydrocannabinol (THCCOOH), have not been extensively studied. We aim to further characterize postmortem concentrations of THC and THCCOOH in peripheral blood with and without preservation, central blood, and central serum to support improved forensic interpretation. Cannabinoids were extracted from blood and serum from twenty-five decedents using solid phase extraction followed by quantification using gas chromatography - mass spectrometry. We evaluated the impact of sample preservation, reported central blood-to-peripheral blood (CBPB) ratios and blood-to-serum ratios, and assessed the relationship of CBPB and postmortem interval for THC and THCCOOH. Correlations of preserved compared to unpreserved blood were strong with r