Determination of zaleplon and zolpidem by liquid chromatography–turbo-ionspray mass spectrometry: application to forensic cases

• Published in: Journal of chromatography. B 2003-06, Vol.789 (1), p.131-138
• Main Authors: Giroud, Christian, Augsburger, Marc, Menetrey, Annick, Mangin, Patrice
• Format: Article
• Language: English
• Subjects: Acetamides - blood; Biological and medical sciences; Chromatography, Liquid - methods; Drug intoxications. Doping; Forensic Medicine; Humans; Hypnotics and Sedatives - blood; Mass Spectrometry - methods; Medical sciences; Pharmacology. Drug treatments; Pyridines - blood; Pyrimidines - blood; Reference Standards; Reproducibility of Results; Zaleplon; Zolpidem
• ISSN: 1570-0232; 1873-376X
• DOI: 10.1016/S1570-0232(03)00135-1

Zolpidem and zaleplon are two short-acting hypnotic agents used in Europe and in the USA. An atmospheric pressure ionisation liquid chromatography–mass spectrometry (Sciex API 150 EX) method was developed for the determination of zolpidem and zaleplon in whole blood. After single-step liquid–liquid extraction, the hypnotics were separated by gradient-elution with an ammonium formate buffer/acetonitrile eluent on an Inertsil ODS-3 column. Methaqualone was used as internal standard. The recovery was higher than 70% for both hypnotics and the internal standard. The best fit for the calibration curve was achieved, between 1 and 250 ng/ml, with 1/ x quadratic regression. Coefficients of intra- and inter-assay variation calculated at 5, 25 and 100 ng/ml were less than 10%. The method was successfully applied to forensic cases.