Determination of six fluoroquinolones in aquatic products by QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry

Objective To establish a method for the determination of norfloxacin, ciprofloxacin, lomefloxacin, enrofloxacin, ofloxacin and pefloxacin in aquatic products by QuEChERS with ultra performance liquid chromatographytandem mass spectrometry (UPLC-MS/MS). Methods Six fluoroquinolones in aquatic products were extracted by 1% formic acid acetonitrile solution, purified by QuEChERS, separated by C18 column (2.1 mm×100 mm, 1.7 μm) using 0.1% formic acid and methanol-acetonitrile (4∶6, V/V) as mobile phases, then identified and quantified by UPLC-MS/MS. Results Norfloxacin, ciprofloxacin, lomefloxacin, enrofloxacin, ofloxacin and pefloxacin had good linear relationships in a certain concentration range with correlation coefficients (r) above 0.999. The limits of detection of six fluoroquinolones were 0.30-0.80 μg/kg, and limits of quantification were 1.0-2.5 μg/kg. The average recoveries of the method were between 86.6% and 120%, and the relative standard deviations were between 0.59% and 7.6%. Conclusion The method was rapid and accurate, and was suitable for rapid screening and analysis of the six fluoroquinolones in aquatic products.