title: Quantitative LC-MS determination of strychnine in urine after ingestion of a Strychnos nux-vomica preparation and its consequences in doping control.
abstract: A simple, fast and sensitive method for the quantitative determination of strychnine residues in urine has been developed and validated. The method consists of a liquid-liquid extraction step with ethyl acetate at pH 9.2, followed by LC-MS/MS in positive atmospheric pressure chemical ionization (APCI)-mode. The method is linear in the range of 1-100 ng/mL and allows for the determination of strychnine at sub-toxicological concentrations. The accuracy of the method ranged from 1.3% to 4.4%. The method was used to determine the excretion profile of strychnine after the ingestion of an over-the-counter herbal preparation of Strychnos nux-vomica. Each volunteer ingested a dose equivalent to 380 micro g of strychnine. This dose is lower than the prescription dose but results in the detection of strychnine for over 24-h post administration. Maximum detected urinary concentrations ranged from 22.6 to 176 ng/mL. The results of this study show that the use of this type of preparation by athletes can lead to a positive doping case.
authors.affiliation: Doping Control Laboratory (DoCoLab), Ghent University-UGent, Department of Clinical Biology, Microbiology and Immunology, Technologiepark 30B, B-9052 Zwijnaarde, Belgium. peter.vaneenoo@ugent.be
authors.forename: P
authors.initials: P
authors.lastname: Van Eenoo
authors.forename: K
authors.initials: K
authors.lastname: Deventer
authors.forename: K
authors.initials: K
authors.lastname: Roels
authors.forename: F T
authors.initials: FT
authors.lastname: Delbeke
mesh_terms: D004300:Doping in Sports; D053593:Forensic Toxicology; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008297:Male; D009269:Nalorphine / Q000652:urine; D009292:Narcotic Antagonists / Q000652:urine; D009294:Narcotics / Q000652:urine*; D004366:Nonprescription Drugs / Q000008:administration & dosage / Q000737:chemistry; D013331:Strychnine / Q000652:urine*; D031461:Strychnos nux-vomica / Q000737:chemistry*; D015813:Substance Abuse Detection / Q000379:methods*
chemical_list: D009292:Narcotic Antagonists; D009294:Narcotics; D004366:Nonprescription Drugs; D013331:Strychnine; D009269:Nalorphine