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.