Abstract: A confirmative method of ultra performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) for the simultaneous determination of 7 fluoroquinolone residues (norfloxacin (NOR), ciprofloxacin (CIP), danofloxacin (DAN), enrofloxacin (ENR), ofloxacin (OFL), sarafloxacin (SAR) and marbofloxacin (MAR)) in chicken muscle was developed. The sample was extracted with acidified acetonitrile, defatted with n-hexane, and purified by an HLB solid phase extraction cartridge. The UPLC separation was performed on an ACQUITY UPLCTM BEH C18 column (50 mm×2.1 mm, 1.7 μm) utilizing a gradient elution program of acetonitrile and water (containing 0.1% formic acid) as the mobile phase. The identification and quantification were achieved by using ESI-MS/MS in positive ion mode and multiple reaction monitoring (MRM). The linear ranges were from 5 to 100 μg/kg with the correlation coefficients above 0.99 for all the 7 fluoroquinolones. The average recoveries spiked at the 3 concentration levels of 5, 25, 50 μg/kg ranged from 79.2% to 108.6% with the relative standard deviations of 4.2%~8.9%. The limits of detection were 0.2~1.4 μg/kg. The method was proved to be good reproducibility, high sensitivity, rapid, reliable and suitable for the simultaneous determination of multi-residues of fluoroquinolones in chicken muscle.

Key words: chicken muscle , fluoroquinolones, solid phase extraction (SPE), ultra performance liquid chromatography-electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS)