Rotenone Analysis by Liquid Chromatography-Tandem Mass Spectrometry with Information-Dependent Acquisition in a Fatal Case of Rotenone Poisoning with a Commercial Organic Insecticide Being Sold in Korea

Rotenone is a neurotoxin derived from Derris roots or yam bean of genus Derris or Lonchocarpus. It is known to cause Parkinson-like symptoms and is a potent electron transport inhibitor. Rotenone was detected in postmortem specimens in a fatal case of rotenone poisoning with an organic pesticide by liquid chromatography-tandem mass spectrometry with an information-dependent acquisition and MS-MS library search. The forensic specimens were prepared by solid-phase extraction with a Bond Elut(A (R)) Certify cartridge. The mobile phase comprised 5 mM ammonium formate in 10% methanol and 5 mM ammonium formate in 90% methanol. The assay was linear over the range from 0.01 to 1.0 mg/L (r(2) = 0.995). The limit of detection and quantitation in the blood were 0.001 mg/L (signal-to-noise, S/N = 3) and 0.003 mg/L (S/N = 10), respectively. The intraday accuracy and precision for rotenone that were determined by five replicates at 0.02, 0.10 and 1.0 mg/L in blood were < 15.0% of bias and < 9.0% of CV, respectively. The interday accuracy and precision for rotenone that were determined by seven replicates at 0.02, 0.10 and 1.0 mg/L in blood were < 18.0% of bias and < 17.0% of CV, respectively. Relative recovery with 0.02, 0.1 and 1.0 mg/L in blood was 104.2, 103.3 and 81.6% (n = 6), respectively. The described method was applied for the determination of rotenone in a fatal case of intoxication of a 33-year-old man who was found dead on a bed in a temporary house. In this case study, the concentrations of rotenone in heart blood (HB), peripheral blood (PB), gastric contents and vitreous humor were 0.77 mg/L, 0.02 mg/L, 126.4 mg/kg and 0.003 mg/L, respectively. The rotenone concentration ratio of the HB/PB was 38.8 and that of gastric contents/PB was 6412.3, suggesting a massive ingestion of rotenone with postmortem redistribution. This study is the report of rotenone detection in a fatal case with the ingestion of the organic insecticide containing rotenone.