title: Luminescence screening of enrofloxacin and ciprofloxacin residues in swine liver after dispersive liquid-liquid microextraction cleanup.
abstract: A luminescence method was developed to screen residues of enrofloxacin (ENRO) and its metabolite, ciprofloxacin (CIPRO), in swine liver. Target analytes were extracted in acetonitrile/1.5% trifluoroacetic acid/NaCl, cleaned up by dispersive liquid-liquid microextraction (DLLME), and finally detected by terbium-sensitized luminescence (TSL) using a time-resolved luminescence photometer. CIPRO yielded slightly lower TSL response than ENRO, so a common threshold was derived from CIPRO and applied to both fluoroquinolones. Among 37 samples randomly spiked with CIPRO or ENRO up to 1 μg/g, all 19 samples spiked above the 500 ng/g tolerance were correctly screened as positive with no false negatives, but 3 of 18 samples spiked below 500 ng/g were classified as positive. This method minimized the use of chlorinated solvents and significantly improved sample throughput.
authors.affiliation: Eastern Regional Research Center, Agricultural Research Service, US Department of Agriculture, Wyndmoor, Pennsylvania 19038, United States. guoying.chen@ars.usda.gov
authors.forename: Guoying
authors.initials: G
authors.lastname: Chen
authors.forename: Qiongqiong
authors.initials: Q
authors.lastname: Li
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D002939:Ciprofloxacin / Q000032:analysis*; D004350:Drug Residues / Q000032:analysis*; D000077422:Enrofloxacin; D024841:Fluoroquinolones / Q000032:analysis*; D059627:Liquid Phase Microextraction / Q000379:methods*; D008099:Liver / Q000737:chemistry*; D049449:Luminescence; D013552:Swine
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D000077422:Enrofloxacin; D002939:Ciprofloxacin