Determination of nimetazepam and its metabolites in rat urine by SPE-GC/MS

Objective To determine the metabolites of nimetazepam in rat.Methods Two Wistar rats were administered a pill of nimetazepam respectively,and urine fractions in 24 h were collected.After enzymatic hydrolysis of the urine samples,nimetazepam and its metabolites were extracted by Oasis HLB solid-phase extraction and analyzed by GC/MS with DB-35 MS column.Results Four metabolites for nimetazepam as 7-acetylaminonimetazepam,7-acetylaminonitrazepam,7-aminonimetazepam and 2-amino-5-nitrophenylphenylmethanone and a little nimetazepam were identified in the urine.Conclusion Nimetazepam was metabolized easily in rat and 7-acetylaminonimetazepam and 7-acetylaminonitrazepam were the main metabolites in rat urine.