Confirmation of Gelsemium elegans poisoning by UHPLC–MS/MS analysis of koumine, gelsemine, and gelsenicine in hair

•First LC-MS/MS for determination of gelsenicine, gelsemine, and koumine in human hair.•Application to measure hair concentration in a Gelsemium poisoning case.•Deposition of koumine, gelsemine, and gelsenicine in human hair after a single dose of Gelsemium. A sensitive, accurate, simple, and rapid analytical UHPLC–MS/MS method was developed for identification and quantification of koumine, gelsemine, and gelsenicine in human hair. Approximately 10 mg of hair was extracted with methanol by cryogenic grinding. The limits of detection (LODs) ranged from 1 to 5 pg/mg, and the limits of quantitation (LOQs) ranged from 2 to 10 pg/mg. The method was linear over a concentration range from the LOQs to 1000 pg/mg, and the linear correlation (R2) of the calibration curves was above 0.998 for all three analytes. The bias varied from −6.5–13.1%, while the intra- and inter-day precision relative standard deviation (RSD) values were 4.3–12.4% and 3.7–13.2%, respectively. Recoveries ranged from 79.3% to 103.5%, and matrix effects ranged from 74.3% to 105.5%. The described method was used for the quantitative determination of koumine, gelsemine, and gelsenicine in a human hair sample from a Gelsemium elegans poisoning case. The highest concentrations of koumine, gelsemine, and gelsenicine were 27.2, 18.1, and 4.2 pg/mg, respectively, and corresponded to the segment associated with the ingestion period. To our knowledge, this is the first study to describe hair analysis in a G. elegans poisoning case and to provide quantitative toxicological findings.