卫生研究

目的应用数据库建立陈皮、荷叶、葛根、胖大海等代用茶中农药残留筛查方法,对4种代用茶中26种农药残留的分散固相萃取-气相色谱-串联质谱(gas chromatography-tandem mass spectrometry, GC-MS/MS)分析方法进行确证。方法选择筛查出来的农药、代用茶种植中实际使用农药及禁限用农药共26种作为目标化合物。样品经乙腈提取后,经吸附剂(如PSA、GCB、C₁₈)净化,以DB-5MS UI柱[(15 m+PUU+15 m)×0.25 mm×0.25μm]程序升温分离,采用GC-MS/MS在多反应监测模式下检测,外标法定量。结果 26种农药在2～100μg/L浓度范围内线性关系良好,r≥0.995,方法定量限为3～40μg/kg。以空白基质进行3个浓度水平(10、50和200μg/kg)的加标回收实验,平均回收率为71.9%～114.4%,相对标准偏差为1.0%～16.0%(n=6)。4种代用茶检测结果表明,农药集中在陈皮上,并且有多种残留农药。结论该方法简单快速、灵敏度高、选择性好,可满足陈皮、荷叶、葛根、胖大海等代用茶中农药筛查和多残留分析的要求。

OBJECTIVE The screening method was established for pesticide residues in substitutional teas such as orange peel, lotus leaf, pueraria lobata and Pangdahai using data base. The method for analyzing of 26 pesticide residues was confirmed in four substitutional teas with gas chromatography-tandem mass spectrometry(GC-MS/MS) and dispersive solid-phase extraction(d-SPE) for sample preparation. METHODS The 26 types of pesticides were selected as target compounds, including screened out, commonly used in substitutional tea planting and forbidden in agriculture planting. The samples extracted with acetonitrile, and purified by adsorbent(e.g PSA, GCB, C₁₈), the purification solutions were separated on DB-5 MS UI column((15 m+PUU+15 m)×0.25 mm×0.25 μm) with programmed temperature and determined by GC-MS/MS in multi-reaction monitoring(MRM) model. The external standard method was applied to quantify the pesticides. RESULTS The method showed a good linearity(r≥0.995)in concentration range(2-100 μg/L) for 26 kinds of pesticides. The limits of quantification(LOQ) were 3-40 μg/kg. The average recoveries range were 71.9%-114.4% in three add levels of 10, 50, 200 μg/kg, and relative standard deviations of 1.0%-16.0%(n=6).In the four matrixes, the pesticides were detected concentrating on orange peel, and there were kinds of residues. CONCLUSION This method is simple, fast, sensitive, selective and can satisfy the request of pesticide screening and simultaneous analysis of multiple pesticide residues in orange peel, lotus leaf, pueraria lobata and Pangdahai.