Determination of Residual Amounts of Orbifloxacin in Food by UHPLC and LC-MS/MS

The food sample was extracted with acetonitrile and phosphate buffer solution,and defatted with n-hexane and purified by passing through HLB SPE column.The eluate obtained was determined by UHPLC with fluorescence detector,and positive results were further confirmed by LC-MS/MS.Linearity ranges of orbifloxacin obtained by the two method were found to be in the ranges of 0.005-0.250 mg·L-1 (by UHPLC) and 0.002-0.300 mg·L-1 (by LC-MS/MS),and values of detection limits (3S/N) found were 0.005 and 0.002 mg·kg-1 respectively.Values of recovery ranged from 80.2%-98.4% (for UHPLC) and from 74.5%-93.0% (for LC-MS/MS),were found with RSD′s (n=10) less than 11.0%.