QuEChERS结合超高效液相色谱串联质谱法测定花椒中烯效唑残留量及贮藏稳定性

该研究建立超高效液相色谱-串联质谱法(ultra performance liquid chromatography tandem mass spectromentry,UPLS-MS/MS)测定花椒中烯效唑残留量的检测方法,并测定花椒样品中烯效唑残留量以及低温条件下烯效唑在花椒中贮藏稳定性研究。样品经0.1%(体积分数)乙酸乙腈涡旋提取,经PSA+GCB净化剂净化后,采用C 18色谱柱分离,在正离子模式下UPLC-MS/MS测定。结果表明,烯效唑溶剂标准曲线和基质标准曲线在1.0~50.0 ng/mL线性良好,相关系数(R 2)为0.9937~0.9997。在0.02、0.05、0.20 mg/kg 3个添加浓度下,方法的回收率为71.50%~85.98%,相对标准偏差为1.13%~5.36%。烯效唑方法定量限为0.02 mg/kg;花椒在-20℃贮藏条件下烯效唑的平均降解率均<30%,说明烯效唑在花椒样品中至少可以稳定贮藏150 d。该方法操作简单、灵敏度高、准确可靠,适用于鲜花椒、干花椒中烯效唑的检测,可为解决烯效唑在食品中残留的安全问题提供技术支撑。

Determination of uniconazole and storage stability in Zanthoxylum bungeanum Maxim by QuEChERS-UHPLC-MS/MS

A method for the simultaneous determination of uniconazole in Zanthoxylum bungeanum Maxim by ultra performance liquid chromatography tandem mass spectrometry(UHPLC-MS/MS)was established.The experimental samples were extracted with acetonitrile containing 0.1%acetic acid and purified with PSA and GCB.The mobile phase was eluted with acetonitrile and 0.1%formic acid aqueous solution.The analytes were separated on an Hypersil GOLD C 18 column and quantitatively analyzed by the external standard method using matrix-matched calibration curves.The results showed that there was good linearity in the range of 1.0-50 ng/mL under the optimal conditions,with correlation coefficients R 2 of 0.9937-0.9997.The spiked recoveries of uniconazole in Zanthoxylum bungeanum Maxim at three spiked levels of 0.02,0.05,0.20 mg/kg ranged from 71.50%to 85.98%,with relative standard deviations RSDs of 1.13%-5.36%.The limits of quantitation of LOQ were 0.02 mg/kg.Moreover,the average degradation rate of uniconazole in Zanthoxylum bungeanum Maxim was less than 30%at-20℃.The established method was simple,sensitive,accurate and reliable,and could meet the requirement of multi pesticide residues analysis in mango skin and flesh.It was of great significance to solve the safety problems for the residue of uniconazole in foods.