Capillary electrochromatography–electrospray ionization mass spectrometry for the qualitative investigation of the drug etodolac and its metabolites in biological samples

On-line coupling of capillary electrochromatography (CEC) with electrospray ionization (ESI) mass spectrometry (MS) was used for the qualitative investigation of the biotransformation of the non-steroidal anti-inflammatory drug etodolac. The coupling of this electro-driven separation technique with mass spectrometry allowed us to demonstrate the presence of different metabolites of etodolac extracted from human urine.