高效液相色谱-串联质谱法测定黄瓜中嘧菌酯残留

Determination of azoxystrobin residue in cucumber by high performance liquid chromatography-tandem mass spectrometry

目的建立高效液相色谱-串联质谱法测定黄瓜中的嘧菌酯残留量的分析方法。方法样品用乙腈匀浆提取,无水硫酸镁、氯化钠盐析离心,无水硫酸镁、PSA净化,用液相色谱-串联质谱仪测定,外标法定量。结果在选定色谱条件下,嘧菌酯的检出限为1.0×10-12g;在质量浓度0.0025~0.50μg/mL范围内,嘧菌酯的峰面积与浓度呈线性关系,标准曲线方程为:Y=2×108X-51888,相关系数r为0.9995;分别在0.005、0.05、0.5 mg/kg 3个添加水平进行添加回收实验,平均回收率为86%~93%,相对标准偏差(relative standard deviation,RSD)为6.0%~7.4%,嘧菌酯在黄瓜中的定量限为0.005mg/kg。结论该方法前处理过程简洁,减少了系统误差,节约了样品处理时间;检测方法灵敏度高,准确度和精密度满足NY/T 788-2018《农作物中农药残留试验准则》的要求,适用于黄瓜中嘧菌酯残留量的检测。

Objective To establish a method for determination of azoxystrobin residue in cucumber by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Methods Samples was extracted by acetonitrile after homogenate, centrifugated with anhydrous magnesium sulfate and sodium chloride, purified by PSA and anhydrous magnesium sulfate, then detected by HPLC-MS/MS, and calculated by external standard method. Results Under the selected chromatographic conditions, the limit of detection of azoxystrobin was 1.0×10^-12 g. In the range of 0.0025-0.50 μg/mL, there was a good linear relationship between peak area and concentration, with the standard curve equation of Y=2×10^8 X=51888, and the correlation coefficient of 0.9995. The recoveries at 3 spiked levels (0.005, 0.05, 0.5 mg/kg) were 86%-93%, with the relative standard deviations (RSD) were 6.0%-7.4%. The limit of quantification (LOQ) in cucumber was 0.005 mg/kg. Conclusion The pretreatment process of this method is simple, which reduces the system error and saves the sample processing time. The established method has high sensitivity, accuracy and precision, meeting the requirements of NY/T 788-2018 Guideline for the testing of pesticides in crops, which is suitable for the detection of azoxystrobin residue in cucumber.