茶叶中甲基对硫磷、对硫磷农药残留分析及安全性评价

Residue analysis and security judgement of parathion-methyl and parathion residues in tea

目的:应用高效液相色谱法结合基质固相分散技术,对不同茶类中对硫磷和甲基对硫磷农药残留量进行检测。方法:茶叶样品采用基质固相分散方法进行预处理,经中性Al_(2)O_(3)研磨分散后,以乙酸乙酯—正己烷(V_(乙酸乙酯)∶V_(正己烷为8%))洗脱,浓缩定容,经高效液相色谱检定。结果:该方法简便、快速、准确;呈良好的线性相关,甲基对硫磷和对硫磷的线性相关系数分别为0.9996,0.9995;方法检出限分别为0.015,0.006 mg/kg;加标回收率分别为90.67%,86.67%。此外,甲基对硫磷和对硫磷的检出率分别为7.69%,19.23%,平均残留量分别为0.0048,0.0085 mg/kg。不同茶叶中对硫磷和甲基对硫磷的残留水平不同。甲基对硫磷和对硫磷的平均日摄入量分别为0.0236,0.1041μg/(kg·d·BW)。结论:不同茶样中甲基对硫磷和对硫磷的残留问题并不突出,其残留量均未超标;对硫磷的检出概率和残留量均高于甲基对硫磷的;乌龙茶、红茶和绿茶中检出对硫磷的概率较高,但不会对一般消费者产生因饮茶所导致的健康风险问题。

Objective:To detect the level of parathion-methyl and parathion residues in different types of tea by high pressure liquid chromatography coupled with matrix solid phase dispersion.Methods:Before determined by high pressure liquid chromatography(HPLC),the tea samples were pretreated by matrix solid phase dispersion method grinding with neutral alumina as dispersant and eluting by ethyl acetate:n-hexane(8%).Results:The results showed that this method was simple,rapid and accurate,with good linearity(0.9996 for parathion-methyl and 0.9995 for parathion),low detection limits(0.015,0.006 mg/kg,respectively)and high recoveries(90.67%and 86.67%,respectively).Incidence of parathion-methyl and parathion occurred with a frequency of 7.69%and 19.23%,and the average concentration of 0.0048 mg/kg and 0.0085 mg/kg,respectively.The residue levels varied from tea types.The corresponding average daily intake of parathion-methyl and parathion by drinking was 0.0236 and 0.1041μg/(kg·d·BW),respectively.Conclusion:The problem of methyl parathion and parathion residues in different tea samples was not prominent,and their residues did not exceed the standard.The detection probability and residue of parathion were higher than those of methyl parathion.The probability of parathion detection in oolong tea,black tea and green tea was higher,but the analysis data showed that there was no health risk problem caused by drinking tea for general consumers.