Application of a hybrid ion trap/time-of-flight mass spectrometer in metabolite characterization studies: Structural identification of the metabolism profile of antofloxacin in rats rapidly using MS n information and accurate mass measurements

Abstract

We describe herein, a very effective way in the rapid identification of metabolites for antofloxacin based on a hybrid ion trap (IT)/time-of-flight (TOF) mass spectrometer technique. The purified samples were separated by a reversed-phase C 18 column under a gradient elution, antofloxacin and its metabolites were detected by the on-line IT/TOF detector in scan mode. The identification of the metabolites and elucidation of their structure were performed by comparing the changes in molecular masses (Δ M), calculating compound-based component by Formula Predictor software, and defining sites of biotransformation based upon mass shifts of diagnostic fragment ions according to the accurate MS n spectral information. In this case, we used such strategies for the identification of the metabolism for antofloxacin, and six metabolites of antofloxacin were found in rats for the first time.