气相色谱-质谱联用法测定茶叶中21种农药残留

Determination of 21 pesticide residues in tea by GC-MS

该实验建立了茶叶中21种农药残留的气相色谱-质谱(GC-MS)多反应监测模式(MRM)定性、定量分析检测方法,探讨不同提取方法、提取溶剂、浓缩方式等试验因素对茶叶农药多残留测定结果的影响。结果表明,以正己烷-丙酮(1∶1,V/V)混合溶剂超声提取、氮吹浓缩,用气相色谱-质谱法对茶叶样品中21种农药进行定性定量检测,21种农药在0.05～1.00μg/mL范围内呈良好的线性关系,相关系数(R^2)为0.9980～0.9999。在茶叶样品中分别添加质量浓度0.05mg/kg、0.20mg/kg、0.40mg/kg的农药组分,平均回收率为83.46%～92.13%,相对标准偏差(RSD)为4.88%～8.51%,检出限为0.0027～0.0219mg/kg,该方法具有前处理简便快捷、灵敏度高、成本低等优点,在实际茶叶农药残留检测中得到了广泛应用,能满足日常的茶叶农药残留检测。

A determination method for qualitative and quantitative analysis of 21 kinds of pesticides residues in tea was developed by GC-MS combined with MRM mode. The effects of different extraction methods, solvents and concentration methods on the determination of pesticide residues in tea were investigated. Results showed that using ultrasonic extraction of n-hexane+acetone(1∶1, V/V) mixed solvent and concentration by nitrogen blowing, the 21 kinds of pesticides were qualitatively and quantitatively detected, and the pesticides were in good linearity in the concentrations of 0.05-1.00 μg/ml(correlation coefficient R^2 were 0.998 0-0.9999). After adding the spiked levels of 0.05 mg/kg, 0.2 mg/kg, 0.4 mg/kg, the average recoveries varied from 83.46% to 92.13%, and the relative standard deviations(RSD) ranged from 4.88% to 8.51%, and the limit of detection was 0.002 7-0.0219 mg/kg. The method had the advantages of simple pretreatment, high sensitivity, high accuracy and low cost, the method was widely used in the practical detection of pesticide residues in tea, which met the requirements daily detection of pesticide residues in tea.