Distribution of ∆⁹‐Tetrahydrocannabinol and 11‐Nor‐9‐Carboxy‐∆⁹‐Tetrahydrocannabinol Acid in Postmortem Biological Fluids and Tissues From Pilots Fatally Injured in Aviation Accidents

Abstract

Little is known of the postmortem distribution of ∆(9)-tetrahydrocannabinol (THC) and its major metabolite, 11-nor-9-carboxy-∆(9)-tetrahydrocannabinol (THCCOOH). Data from 55 pilots involved in fatal aviation accidents are presented in this study. Gas chromatography/mass spectrometry analysis obtained mean THC concentrations in blood from multiple sites, liver, lung, and kidney of 15.6 ng/mL, 92.4 ng/g, 766.0 ng/g, 44.1 ng/g and mean THCCOOH concentrations of 35.9 ng/mL, 322.4 ng/g, 42.6 ng/g, 138.5 ng/g, respectively. Heart THC concentrations (two cases) were 184.4 and 759.3 ng/g, and corresponding THCCOOH measured 11.0 and 95.9 ng/g, respectively. Muscle concentrations for THC (two cases) were 16.6 and 2.5 ng/g; corresponding THCCOOH, "confirmed positive" and 1.4 ng/g. The only brain tested in this study showed no THC detected and 2.9 ng/g THCCOOH, low concentrations that correlated with low values in other specimens from this case. This research emphasizes the need for postmortem cannabinoid testing and demonstrates the usefulness of a number of tissues, most notably lung, for these analyses.

Distribution of tetrahydrocannabinol and cannabidiol in several different postmortem matrices

“…Peripheral blood is the matrix that is considered to be the gold standard for interpretation and quantitation of drug concentrations [13]. Other matrices might provide important information regarding concentrations of both THC and CBD, but very few studies have investigated postmortem concentration of cannabinoids, and postmortem distribution [5,15,16]. Since THC is highly lipophilic, it can be stored longer in the adipose tissues of the body relative to other organs and this can affect the distribution of THC through the body.…”

“…In such cases, other matrices must be analysed. A few studies have investigated the postmortem distribution of THC and its major metabolites [5,15,16], and postmortem redistribution of THC and metabolites [5,17,18], or CBD [19].…”

Plasma vs heart tissue concentration in humans – literature data analysis of drugs distribution

“…The corresponding heart THCCOOH concentrations were 11.0 ng/g and 95.9 ng/g, respectively. The examination lacked corresponding blood samples allowing a comparison of drug concentrations [124].…”

Postmortem Fluid and Tissue Concentrations of THC, 11-OH-THC and THC-COOH†

“…Our laboratory currently utilizes solid-phase extraction (SPE) and gas chromatography with negative chemical ionization mass spectrometry (GC/MS-NCI) for the analysis of THC and THC-COOH in postmortem fluids and tissues. (17) While our current method is suitable for the analysis of postmortem fluids and tissues for THC and THC-COOH, there are a few limitations with this method: our extraction requires 3 mL of fluid specimen, GC/MS analysis requires multiple time-consuming derivatizations, GC/MS-NCI relies on retention time and the M-H ion only for identification, and it does not detect 11-OH-THC.…”

“…Furthermore, there have been a limited number of studies published on the distribution of these cannabinoids in postmortem fluids and tissues. (17)(18)(19) This paper details the validation and application of SPE coupled with LC/MS/MS for the identification and quantitation of THC, 11-OH-THC, and THC-COOH in postmortem fluid and tissue specimen from 11 aviation accident fatalities.…”