title: Multiresidue determination of fluoroquinolones in shrimp by liquid chromatography-fluorescence-mass spectrometry.
abstract: An efficient multiresidue method for analysis of fluoroquinolones in shrimp has been developed in which quantitation by fluorescence and confirmation by Multiple Stage Mass Spectrometry (MS) is achieved simultaneously. In this method, shrimp tissue is extracted with ammoniacal acetonitrile and the extract is defatted and then evaporated. After dissolution in basic phosphate buffer, fluoroquinolones in the extract are separated by liquid chromatography and quantitated, taking advantage of their intense fluorescence. Eluate from the fluorescence detector enters the MS, which allows for confirmation by monitoring ratios of 2 prominent product ions in the MS3 or MS2 spectrum. Using this method, 8 fluoroquinolones have been analyzed in shrimp samples fortified at 10, 25, 50, or 100 ppb levels. Recoveries for desethyleneciprofloxacin, norfloxacin, ciprofloxacin, danofloxacin, enrofloxacin, orbifloxacin, sarafloxacin, and difloxacin ranged from 75 to 92%, with relative standard deviation values of <6%. The limits of quantitation ranged from 0.1 to 1 ng/g. Enrofloxacin and ciprofloxacin were also successfully determined in enrofloxacin-incurred shrimp using this method.
authors.affiliation: U.S. Department of Agriculture, Eastern Regional Research Center, Agricultural Research Service, 600 E. Mermaid Ln, Wyndmoor, PA 19038, USA. mschneider@errc.ars.usda.gov
authors.forename: Marilyn J
authors.initials: MJ
authors.lastname: Schneider
authors.forename: Luz
authors.initials: L
authors.lastname: Vazquez-Moreno
authors.forename: Maria del Carmen
authors.initials: Mdel C
authors.lastname: Bermudez-Almada
authors.forename: Ramon Barraza
authors.initials: RB
authors.lastname: Guardado
authors.forename: Magdalena
authors.initials: M
authors.lastname: Ortega-Nieblas
mesh_terms: D000097:Acetonitriles / Q000494:pharmacology; D000818:Animals; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods*; D002939:Ciprofloxacin / Q000031:analogs & derivatives / Q000032:analysis; D004350:Drug Residues / Q000032:analysis*; D000077422:Enrofloxacin; D024841:Fluoroquinolones / Q000032:analysis*; D005504:Food Analysis / Q000379:methods; D005506:Food Contamination; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D009643:Norfloxacin / Q000032:analysis; D033561:Penaeidae; D012758:Shellfish / Q000032:analysis*; D013997:Time Factors
chemical_list: D000097:Acetonitriles; D024841:Fluoroquinolones; C054029:ciprofloxacin-7-ethylenediamine; C068581:danofloxacin; D000077422:Enrofloxacin; D002939:Ciprofloxacin; C047225:difloxacin; C095163:orbifloxacin; D009643:Norfloxacin; C047224:sarafloxacin; C032159:acetonitrile