Determination of the enantiomers of bunolol in human urine by high-performance liquid chromatography on a chiral AGP stationary phase and identification of their metabolites by gas chromatography-mass spectrometry.

A high-performance liquid chromatographic method using a chiral AGP column was developed to screen and determine the enantiomers of bunolol in human urine. The recovery of (+)- and (-)-bunolol from urine was 91.79-95.23% at different concentrations. The coefficients of variation (C.V.) were less than 2.1 and 2.3% for intra- and inter-assays, respectively. Urinary metabolites were detected using GC-MS after derivatization with N-methyl(trimethylsilyl)trifluroacetamide. The influences of pH and modifier on a chiral AGP column were studied.