title: Determination of ofloxacin enantiomers in sewage using two-step solid-phase extraction and liquid chromatography with fluorescence detection.
abstract: A robust analytical method has been developed and validated for the trace analysis of ofloxacin enantiomers in sewage using two-step solid-phase extraction purification and liquid chromatography with fluorescence detection (LC-FL). Ofloxacin enantiomers were separated on an Aglient TC-C-18 column using MeOH-water containing 4mmol/L CuSO4 and 5mmol/L l-isoleucine as mobile phase. The ofloxacin enantiomers were first extracted by a weak cation-exchange resin (WCX) and eluted with acidified MeOH (0.5% formic acid), then further purified by mixed mode of anion-exchange resin (MAX), resulting in ofloxacin recoveries generally above 95%. The limit of quantification was 0.08microg/L for each enantiomer. No significant matrix effect was found during the analytical procedure and standard solution calibration curves could be used for quantification. Total concentrations of both enantiomers in real sewage samples based on LC-FL method were consistent with those obtained upon liquid chromatography using tandem mass spectrometry (LC-MS/MS) method.
authors.affiliation: Beijing Center for Disease Control and Prevention, Beijing 100013, China. shaobingch@sina.com
authors.forename: Bing
authors.initials: B
authors.lastname: Shao
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Sun
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Jianying
authors.initials: J
authors.lastname: Hu
authors.forename: Huiru
authors.initials: H
authors.lastname: Dong
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D015394:Molecular Structure; D015242:Ofloxacin / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013237:Stereoisomerism; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry
chemical_list: D014874:Water Pollutants, Chemical; D015242:Ofloxacin