Analysis of ibuprofen metabolites by semi-microcolumn liquid chromatography with ultraviolet absorption and pulsed amperometric detectors

Semi-microcolumn (1.5 mm i.d.) liquid chromatography (LC) system with ultraviolet (UV) and pulsed amperometric detector (PAD) was constructed for analysis of ibuprofen metabolites in human urine. PAD was connected in series with the UV detector, and an alkaline solution was post-column added to a mobile phase after the UV detector. By a gradient elution, five ibuprofen metabolites were detected with UV detection from 1 microliter of human urine at 3.5 h after the administration, and information concerning their glucuronation was simultaneously obtained by PAD response.