基质固相分散萃取-高效液相色谱串联质谱法（HPLC-MS-MS）同时测定茶叶中11种农药的残留量

摘要

建立了茶叶中3类11种农药的分散固相萃取-高效液相色谱串联质谱（HPLC-MS-MS）的检测方法。茶叶样品以乙腈-乙酸（体积比99∶1）提取，以PSA为净化剂基质固相分散萃取，然后通过C18色谱柱，以甲醇/水（含甲酸铵）溶液进行梯度洗脱，采用电离喷雾电离方式（ESI+），通过多反应监测（MRM）定量。结果表明：11种农药的分析时间约为20 min，在0~500 ng·mL-1范围内线性相关，相关系数大于0.9995，方法检测限为0.1~1.7μg·kg-1。测定了茶叶样品中11种农药的残留量，加标回收率为62.4%~114.8%（添加水平分别为10~400μg·kg-1），相对标准偏差（RSD）为3.28%~19.34%。选取了5个不同类型的茶叶样品，检测其中11种农药的残留量，检出结果差异较大。其中绿茶中11种农药的检出量为1.7~339.4μg·kg-1，加标回收率为86.1%~104.1%，相对标准偏差（RSD）均小于20%（n=6）。本方法准确、灵敏、简单、快速、安全，能满足茶叶样品中多种农药残留分析的要求。%A method for rapid determination of 11 kinds of pesticide residues in tea samples by matrix solid-phase disperse extraction and high performance liquid chromatography and tandem mass spectrometry was proposed. The pesticide residues in tea sample were firstly extracted by a mixture of V(acetonitrile)∶V(acetic acid)=99∶1, and the extract was solid-phase disperse purified by PSA and then separated on a Waters Xterra MS C18 column with a gradient system of a mixture of methanol and water with ammonium formate. Multi-reaction monitoring (MRM) was employed for quantitative determination. Eleven pesticide residues could be detected within 20 min. The linear range of 11 pesticide residue was 0-500 ng·mL-1 and the limits of detection were between 0.1-1.7μg·kg-1. The correlation rate was more than 0.9995. The average recoveries (spiked at the levels of 10-400μg·kg-1) ranged from 62.4% to 114.8% with relative standard deviation between 3.28% and 19.34%. After extraction and purification, 11 pesticide residues in 5 samples of different kinds of tea with significant variation in content were analyzed. And the residue content of 11 pesticides in green tea sample was 1.7-339.4μg·kg-1. Recoveries in this sample were ranged from 86.1%to 104.1%with relative standard deviations less than 20%. This method is accurate, sensitive, simple, rapid, safe and suitable for identification and quantification of multiple pesticide residues in tea.