Liquid chromatography/photodiode array detection for determination of strychnine in blood: a fatal case report Charlotte Duverneuil a , Geoffroy Lorin de la Grandmaison b , Philippe de Mazancourt a , Jean-Claude Alvarez a,* a Laboratoire de Pharmacologie-Toxicologie, Centre Hospitalier Universitaire Raymond Poincare ´, 104 Boulevard R. Poincare ´, 92380 Garches, France b Service de Me ´decine Le ´gale, Centre Hospitalier Universitaire Raymond Poincare ´, AP-HP, 104 Boulevard R. Poincare ´, 92380 Garches, France Received 1 July 2003; accepted 12 December 2003 Abstract An original liquid chromatography method with photodiode-array detection (DAD) is presented for the determination of strychnine in blood. This sensitive method allows the use of only 0.1 ml of sample. The strychnine was isolated from blood using a liquid–liquid extraction procedure and chloroquine as an internal standard. The limits of detection (LOD) and quantification were 0.06 and 0.5 mg/l, respectively. The recovery was 94% and the coefficients of variation (CV) ranged from 5.9 to 10.8%. A fatal case of strychnine poisoning is presented, with a lethal blood concentration of 25 mg/l. # 2004 Elsevier Ireland Ltd. All rights reserved. Keywords: Strychnine; Forensic toxicology; HPLC; Photodiode-array 1. Introduction Strychnine is an alkaloid that is extracted from the seeds of Strychnos nux vomica, an Indian tree. Strychnos nux vomica usually contains from 1.1 to 1.4% of strychnine, together with an equal amount of the related, toxic alkaloid brucine. Strychnine, which is highly toxic for humans, was used as a rodenticide but is now prohibited in France since 1982. Strychine poisoning was frequent in the last century. Although strychnine intoxication is now a rare event, it may still occur because small amounts of strychnine may still remain in rural areas and because strychnine may be present in street drugs as an adulterant [1]. Strychnine is rapidly absorbed from the gastrointestinal tract and acts upon the central nervous system. It blocks the uptake of the inhibitory neurotransmitter glycine at the postsynaptic receptor site in the motor neurons of the neural horn in the spinal cord, leading to very powerful tonic contractions. The tonic and tetanic contractions of the diaphragm and thoracic abdominal muscles stop the respira- tion, resulting in death. The patient is usually conscious until seconds before death, which allows the differential diagnosis from other convulsive conditions, i.e. epilepsy, tetanus, meningitis or phenothiazine overdoses. According to the literature [2–4], blood concentrations below 2 mg/l are toxic, concentrations between 2 and 10 mg/ l may be lethal, and concentrations above 10 mg/l are fatal. However, one case, in which a blood concentration of 22 mg/l was measured, did not lead to death [5]. The lethal dose of strychnine is reported to be between 50 and 100 mg [2]. Many analytical methods using thin layer chromatogra- phy [6], gas chromatography coupled with mass spectro- metry [3,7] or tandem mass spectrometry [8] and high performance liquid chromatography (HPLC) [9–12] have been previously described, all of them requiring at least 1 ml of sample. However, no HPLC method coupled with photo- diode-array detection (DAD) has been published. In this work a new analytical method using only 0.1 ml of sample is described, based on liquid-liquid extraction and HPLC/DAD for identification and quantification. A case report of fatal Forensic Science International 141 (2004) 17–21 * Corresponding author. Tel.: þ33-1-47-10-79-38; fax: þ33-1-47-10-79-23. E-mail address: jean-claude.alvarez@rpc.ap-hop-paris.fr (J.-C. Alvarez). 0379-0738/$ – see front matter # 2004 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.forsciint.2003.12.010