title: On-line screening for drug metabolites by high-performance liquid chromatography with a diode array UV detector.
abstract: Rapid screening for and selection of potential metabolites of urapidil in dog urine by high-performance liquid chromatographic analysis is achieved by use of a diode array UV detector, which allows multi-wavelength detection and collects several complete UV spectra from each peak in the course of a single chromatographic analysis. Because of the similarity of metabolite spectra to the spectrum of the parent compound, few interesting peaks are picked out, rather rapidly, by means of a selection criterion based on absorption ratios. Inspection of the complete UV spectra of these pre-selected peaks allows further restriction to "candidate" metabolite peaks. Comparison of up-slope, apex and down-slope spectra is a convenient way of testing for peak purity.
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation; D004285:Dogs; D004364:Pharmaceutical Preparations / Q000032:analysis*; D010879:Piperazines / Q000652:urine; D013056:Spectrophotometry, Ultraviolet
chemical_list: D004364:Pharmaceutical Preparations; D010879:Piperazines; C015568:urapidil