Identification of non-steroidal anti-inflammatory drugs and their metabolites in solid phase extracts of human urine using capillary electrophoresis–mass spectrometry

Abstract

The use of capillary electrophoresis (CE) in combination with mass spectrometry (MS) for the identification of a number of non-steroidal anti-inflammatory drugs (NSAIDs) and their metabolites in solid phase extracts of human urine is described. A variety of MS techniques were employed, including tandem mass spectrometry (MS–MS), to profile the extracts. In urine obtained following administration of ibuprofen, the drug itself, its glucuronide metabolite, the hydroxylated metabolite and its corresponding glucuronide, and the carboxylic acid metabolite as the glucuronide were all identified. Similarly, a range of metabolites of flurbiprofen and aspirin, were identified in urine extracts using the hyphenated CE–MS system. These results clearly demonstrate the value of CE–MS for the rapid identification of such substances following their isolation from a biological matrix such as urine.