食品样品用乙腈和磷酸盐缓冲溶液提取,经正己烷脱脂和HLB固相萃取柱净化处理后,用超高效液相色谱(UHPLC)-荧光检测器进行测定,阳性结果再经液相色谱-串联质谱法(LC-MS/MS)进一步确证.两种方法的线性范围分别为0.005~0.250,0.002~0.300 mg·L-1,检出限(3S/N)分别为0.005,0.002 mg·kg-1,回收率分别为80.2%~98.4%,74.5%~93.0%,相对标准偏差(n=10)均小于11.0%.

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%.