高效液相色谱-串联质谱法同时测定鸡蛋中头孢噻肟及其主要代谢物残留

建立了高效液相色谱-串联质谱(HPLC-MS/MS)法同时测定鸡蛋中头孢噻肟及其代谢物去乙酰头孢噻肟残留量的检测方法.样品经乙腈-水(9∶1, V/V)提取,正己烷除脂,C18固相分散萃取除杂,Agilent Eclipse Plus C18色谱柱(100 mm×2.1 mm, 3.5 μm)分离,以0.2%(V/V)甲酸-乙腈为流动相,进行梯度洗脱,目标物采用电喷雾正离子(ESI+)模式电离,多反应监测(MRM)模式检测,基质匹配标准溶液外标法定量.结果表明,头孢噻肟和去乙酰头孢噻肟分别在1.0~143.0 μg/L和1.0~120.0 μg/L浓度范围内线性关系良好(R.2>0.999).方法检出限(LOD, S/N=3)分别为0.07和0.14 μg/kg,定量限(LOQ, S/N=10)分别为0.23和0.99 μg/kg. 在5.0、50.0和100.0 μg/kg 3个添加水平下,头孢噻肟和去乙酰头孢噻肟的回收率分别为83.1%~103.0%和88.2%~101.0%,相对标准偏差(RSD, n=6)均介于2.0%~6.2%.实际样品测定结果表明,本方法简便、快速、灵敏、准确, 可用于鸡蛋中头孢噻肟及去乙酰头孢噻肟的残留分析检测.

Simultaneous Determination of Cefotaxime and Its Main MetabolinResidue in Eggs by High Performance Liquid Chromatography-Tandem Mass Spectrometry

An efficient method for the analysis of cefotaxime and its metabolite desacetylcefotaxime residues in eggs was developed based on high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).The samples were homogenized and extracted with acetonitrile/water (9∶1, V/V) solution.The fat was removed by hexane, and the other impurities were removed with C18 sorbent.The separation of cefotaxime and desacetylcefotaxime was performed on an Agilent Eclipse Plus C18 column (100 mm × 2.1 mm, 3.5 μm) using a mobile phase of 0.2% formic acid(A)-acetonitrile(B) by gradient elution.The analytes were detected by MS/MS in positive electrospray ionization mode (ESI+) and multiple reaction monitoring (MRM), quantitated by matrix-matched extemal standard method.Results showed that the calibration curves had a good linearity in the range of 1.0-143 μg/L (cefotaxime) and 1.0-120 μg/L (desacetylcefotaxime), respectively, with correlation coefficient R.2>0.999.Limits of detection (LOD, S/N=3) for cefotaxime and desacetylcefotaxime were 0.07 and 0.14 μg/kg, and limits of quantitation (LOQ, S/N=10) for cefotaxime and desacetylcefotaxime were 0.23 and 0.99 μg/kg, respectively.At three spiked concentration levels, the recoveries of cefotaxime and desacetylcefotaxime ranged from 83.1% to 103.0% and 88.2% to 101.0%, respectively, both with RSDs (n=6) less than 6.2%.The results demonstrated that the method was simple, quick, sensitive and reliable, and suitable for determination of cefotaxime and desacetylcefotaxime residues in eggs.