QuEChERS-超高效液相色谱-串联质谱法同时测定大米、小麦和动物源食品中异丙隆及其代谢物脱甲基异丙隆残留

本研究建立了超高效液相色谱-串联质谱法(UHPLC-MS/MS)同时测定异丙隆及其代谢物脱甲基异丙隆在大米、小麦、牛肉、牛奶、鸡肉和鸡蛋的残留检测方法。样品经2%甲酸乙腈提取,以N-丙基乙二胺(PSA)净化,利用乙腈和0.2%甲酸水作为流动相梯度洗脱,T3色谱柱分离,在多反应监测模式下定量分析,基质外标法定量。结果表明:异丙隆及其代谢物脱甲基异丙隆溶剂标准曲线和基质标准曲线在1~1 000μg/L范围内线性关系良好,相关系数均大于0.99。在4个加标水平下,异丙隆日内平均回收率为74.0%~107.0%,相对标准偏差0.7%~12.9%;日间平均回收率为76.2%~108.7%,相对标准偏差1.1%~19.8%。脱甲基异丙隆日内平均回收率为76.9%~113.5%,相对标准偏差0.6%~13.9%;日间平均回收率为77.7%~107.4%,相对标准偏差2.2%~17.4%。异丙隆和脱甲基异丙隆的定量限均为1.0μg/kg。该方法简便、快捷、准确、灵敏度高,适用于异丙隆和脱甲基异丙隆在大米、小麦、牛肉、牛奶、鸡肉和鸡蛋6种基质中残留的检测,为解决异丙隆和脱甲基异丙隆在食品中残留的安全问题提供技术方法。

Simultaneous determination of isoproturon and its metabolite desmethyl-isoproturon in rice, wheat and animal foods by QuEChERS-UHPLC-MS/MS

A method for the simultaneous determination of isoproturon and its metabolite(desmethyl-isoproturon) in rice, wheat, beef, milk, chicken and egg samples by ultra performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS) was established. The experimental samples were extracted with 10 mL acetonitrile containing 2% formic acid and purified by matrix dispersion extraction with 50 mg PSA as adsorbent. The mobile phase was eluted with acetonitrile and 0.2% formic acid aqueous solution. The analytes were separated on an ACQUITY UPLC HSS T3 column(2.1 mm×100 mm, 1.8 μm) and quantitatively analyzed by the external standard method using matrix-matched calibration curves. The results showed that the linear relationships between isoproturon and its metabolite desmethyl-isoproturon were good in the range of 1 to 1 000 μg/L, with the correlation coefficients all higher than 0.99. At four spiked levels, the intra-day average recoveries of isoproturon were 74.0%-107.0%(RSD 0.7%-12.9%), the inter-day average recoveries were 76.2%-108.7%(RSD 1.1%-19.8%), respectively. The intra-day average recoveries of desmethyl-isoproturon were 76.9%-113.5%(RSD 0.6%-13.9%), the inter-day average recoveries were 77.7%-107.4%(RSD 2.2%-17.4%), respectively. The limits of quantification(LOQs) were 1.0 μg/kg for isoproturon and desmethyl-isoproturon. The developed method is convenient, rapid, accurate and reliable, which could be applied for the simultaneous detection of isoproturon and desmethyl-isoproturon in rice, wheat, beef, milk, chicken and egg. It was of great significance to solve the safety problems for the residue of isoproturon and desmethyl-isoproturon in foods.