Poison hemlock determination in postmortem samples.

Poison hemlock (Conium maculatum L.) is a weed that grows rampant in many areas of North America. Forensic toxicology laboratories rarely receive requests to analyze biological specimens for the presence of poison hemlock. This report discusses two postmortem cases that were encountered over a decade apart and describes different analytical approaches that may be used to quantify coniine, a primary poison hemlock alkaloid, in biological specimens. The first case is from 2004 and involves a 27-year-old female that was found deceased in a relatively isolated area of California. Based on the presence of plant material at the scene and signs of its ingestion at autopsy, the possibility of hemlock poisoning was considered. Toxicological testing of the blood and gastric content by quantitative selected-ion monitoring Gas Chromatography/Mass Spectrometry (SIM-GC/MS) revealed the presence of coniine at concentrations of 410 ng/mL and 9300 ng/mL, respectively. The second case is from Pennsylvania and was sent for analysis in the spring of 2019. In this case, a male in his forties was found deceased in the kitchen area of a camper. Green substances, in liquid and residue forms, were observed in the sink. Mixtures of leaf-like material were also found in several bowls and pans. Subclavian blood screened positive for coniine by full-scan Gas Chromatography/Mass Spectrometry (GC/MS). Semi-quantitative confirmation testing was performed by Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) and showed the presence of coniine at a concentration of 35 ng/mL. These analytical approaches can be used to substantiate or exclude poison hemlock exposure as a cause of death.

Development and validation of a liquid chromatography-tandem mass spectrometry method for the identification and quantification of JWH-018, JWH-073, JWH-019, and JWH-250 in human whole blood.

A sensitive and specific method for the quantification of JWH-018, JWH-073, and JWH-250 and the qualitative identification of JWH-019 in whole blood was developed and validated. Samples fortified with JWH-018-d9 and JWH-073-d9 underwent liquid-liquid extraction and were analyzed by liquid chromatography-positive ion electrospray ionization-tandem mass spectrometry. Two transitions were monitored for all analytes except JWH-250, for which there was only one available transition. JWH-019 did not meet the stringent requirements for quantitative analysis, and thus this method is only appropriate for the qualitative identification of this compound in whole blood. The linear range was 0.1-20 µg/L for all quantitative analytes. The maximum average within and between-run imprecision was 7.9% and 10.2%, respectively, and all controls quantified within 8.2% of target concentrations. Process efficiency, a measurement that takes into effect extraction efficiency and matrix effect, was ≥ 32.0% for all quantitative analytes; similar results were obtained for the deuterated internal standards. All analytes were stable at room, refrigerated, and frozen temperatures for at least 30 days. The method was used to quantify JWH-018 and JWH-073 in a blood specimen collected from a person known to have used an herbal incense blend containing these substances.