Development of Dried Urine Samples for Simultaneous Quantitative Detection of Sibutramine and Its Active Metabolites by Liquid Chromatography/Mass Spectrometry

Abstract

Sibutramine is an unsafe compound adulterated in weight-loss supplements. Quantitative detection of sibutramine and its active metabolites in urine can signify its ingestion and predict sudden unexpected death due to toxicity following overdose. However, the requirement for cold storage and restrictions on the amount of urine specimens limit downstream procedures. In this study, dried urine spot (DUS) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used for the detection of sibutramine hydrochloride and its metabolites. Spiked drug-free urine was used to prepare DUS. Analytes were accordingly extracted and analyzed by LC-MS/MS with optimum instrumental conditions. The results exhibited that the R² of sibutramine, desmethyl sibutramine and didesmethyl sibutramine were 0.9993, 0.9980 and 0.9993, respectively, and that the limits of detection (LOD) were 0.02, 0.02 and 0.03 ng/mL, respectively. Analytical characteristics and stability affirmed the usability of this newly developed method. These findings favor the application of this analytical protocol toward quantitative detection of sibutramine and its active metabolites using DUS microsampling and LC-MS/MS.