提出了同时测定水产品中加替沙星、莫西沙星和左氧氟沙星的超高效液相色谱-串联质谱分析方法。样品经乙腈提取、正己烷除脂浓缩后用Supelclean LC-SCX固相萃取柱富集,用氨水-甲醇(25+75)溶液洗脱。洗脱液氮气吹干,用乙腈-水(10+90)溶液溶解定容至2.0 mL,取10 μL进行分离测定。以不同体积比的乙腈与5 mmol·L-1乙酸铵的混合溶液为流动相作梯度淋洗,经ACQUITY UPLC BEH C18色谱柱分离,采用电喷雾正离子源及多反应监测模式测定。对3种化合物的质谱裂解规律进行了研究,3种化合物的质量分数在100 μg·kg-1以内呈线性,检出限(3S/N)在3.7~4.8 μg·kg-1之间;以3种水产品样品为基体,在3个标准加入水平下进行回收率和精密度试验,加标回收率在70.5%~83.7%之间,相对标准偏差(n=6)均不大于13%。

A method of UHPLC-MS/MS for simultaneous determination of gatifloxacin, moxifloxacin and levofloxacin in aquatic products was proposed. The samples were extracted with acetonitrile, defatted with n-hexane, and enriched by SPE on Supelclean LC-SCX column. The SPE column was eluted with a mixture of ammonia (aq.) and methanol (25+75), and the eluate obtained was evaporated to dryness by N2-blowing and made up to 2.0 mL with a mixture of acetonitrile and water (10+90). An aliquot of 10 μL was used for UHPLC-MS/MS determination, in which the ACQUITY UPLC BEH C18 column was used as chromatographic column, and mixtures of acetonitrile and 5 mmol·L-1 NH4OAc solution in different ratio were used as mobile phase in gradient elution; positive electrospray ionization as well as multiple reaction monitoring mode were used in the MS detection. Linearity ranges of the compounds were found to be in the ranges within 100 μg·kg-1, with their detection limits (3S/N) in the range of 3.7-4.8 μg·kg-1. Tests for recovery and precision were made by addition of mixed standard solution of the compounds in 3 different concentration levels to 3 samples of aquatic products which were then analyzed by the proposed method. Values of recovery found were in the range of 70.5%-83.7%, and values of RSD′s (n=6) were ≤13%.