title: Determination off four fluoroquinolones in milk by liquid chromatography.
abstract: A liquid chromatographic (LC) method with fluorescence detection is presented for the analysis of 4 fluoroquinolones; enrofloxacin (ENRO), ciprofloxacin (CIPRO), sarafloxacin (SARA), and difloxacin (DIFLX) in milk. The procedure consists of extraction of milk with acidified ethanol, isolation and retention on a cation exchange solid-phase extraction column, elution with basic methanol, and LC analysis with fluorescence detection. LC analysis is performed by isocratic elution using an acetonitrile-2% acetic acid (15 + 85) mobile phase and an Inertsil phenyl column with fluorescence detection at excitation and emission wavelengths of 278 and 450 nm, respectively. A target level of 10 ppb for each of the 4 fluoroquinolones has been established for this method. Average recovery from fortified raw milk samples (5-100 ppb each) based on a 5-point standard curve calculation was 70-90%, with relative standard deviations of < 15%.
authors.affiliation: U.S. Food and Drug Administration, Animal Drugs Research Center, Denver Federal Center, CO 80225-0087, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Roybal
authors.forename: A P
authors.initials: AP
authors.lastname: Pfenning
authors.forename: S B
authors.initials: SB
authors.lastname: Turnipseed
authors.forename: C C
authors.initials: CC
authors.lastname: Walker
authors.forename: J A
authors.initials: JA
authors.lastname: Hurlbut
mesh_terms: D000890:Anti-Infective Agents / Q000032:analysis*; D002853:Chromatography, Liquid; D002939:Ciprofloxacin / Q000031:analogs & derivatives / Q000032:analysis; D000077422:Enrofloxacin; D024841:Fluoroquinolones; D016014:Linear Models; D015363:Quinolones / Q000032:analysis
chemical_list: D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D015363:Quinolones; D000077422:Enrofloxacin; D002939:Ciprofloxacin; C047225:difloxacin; C047224:sarafloxacin