[Simultaneous determination of four fluoroquinolone residues in fish by ion-pair high performance liquid...

An ion-pair high performance liquid chromatographic method with a fluorescence detector was established to determine four fluoroquinolone residues in fish. The chromatographic conditions were as follows: Waters microBondapak C18 column (3.9 mm i.d. x 300 mm, 10 microm) was used at 40 degres C with 11 mmol/L tetrabutylammonium bromide solution (pH 3.0) acetonitrile (94: 6, v/v) as the mobile phase with a flow rate of 1.0 mL/min, at the excitation wavelength of 280 nm and emission wavelength of 460 nm. The detection limit for fish was 1 microg/kg. The linear range was from 6-100 microg/kg, and correlation coefficients were more than 0.9995. At the levels of 10, 50 and 100 microg/kg, the recoveries were 76%-100% with relative standard deviations of less than 7%. The method developed can meet the requirement for residue analysis.