三种农药在茶汤中的浸出及对人体健康影响的风险评价

选择三唑磷、硫丹、氯氟氰菊酯三种农药,在生长均匀的茶园喷施,采摘施药后第2、5、9、14天和21天的茶树鲜叶加工成绿茶,获得含不同浓度农药残留的成茶样品,用气相色谱法测定了农药在成茶、茶汤和茶渣中的残留含量动态,研究表明：成茶和茶汤中的残留水平随施药间隔天数的增加呈逐渐下降趋势,茶汤中农药残留的浓度与成茶中的浓度呈正相关且为线性关系,平均浸出率分别为29.06％(三唑磷)、5.11％(硫丹)、1.73％(氯氟氰菊酯),不溶于茶汤的农药残留大部分存留于茶渣中。将人体因饮茶而摄入的农药残留量与农药ADI相比较,结果表明饮茶摄入的此三种农药的残留对人体健康影响的风险非常小,仅在10^-3~10^-5 水平上。

Extracting Rate of Three Kinds of Pesticide in MadeTea During Brewing Process and Risk Assessment on Human Health

Three kinds of pesticide (Triazophos, Endosulfan and Lambda-cyhalothrin )were sprayed separately in tea garden. The green shoots were harvested from treated plots at 2, 5, 9, 14 and 21 days after the treatment, and manufactured into green tea. The concentration of the above mentioned pesticides in made tea, tea infusion and infused leaves was determined by gas chromatography. Dissipation behavior of pesticide residue in made tea and tea infusion were investigated. Results indicated that the residue level of pesticide in made tea and tea infusion decreased gradually while the plucking interval increased. The concentration of pesticide residue in tea infusion was positively related with that in made tea. The average extracting percentage of residue from made tea to infusion was 29.06%(triazophos)、5.11%(endosulfan)and 1.73%(lambda-cyhalothrin)respectively,and the insoluble residue remained in infused leaves. In comparing the intake amounts of pesticide residue possibly to human body via the tea infusion drinking with ADI of the pesticides, the results showed that the risk to human health from three kinds of pesticide residue by infusion drinking is very small,which is only ranged in 10-3~10-5 level.