Establishment Of Tea Pesticide Residues Detection Method And Its Application

Anxi in Fujian province was the home of Tie Guanyin tea. As the concerns of food safety was strengthened, and the reduced of pesticide residue standards in Tie Guanyin. Now pesticide residues had become an important factor to limit the Tie Guanyin yield and quality. In this study, Tie Guanyin tea was the main material, and a effective method was established to assay the residue of different pesticides (acephate, α-BHC,δ-BHC, fenitrothion, o.p’-DDT, dicofol, permethrin, esfenvalerate, deltamethrin). Using this method, the main of overstandard pesticides was accessed in the crudely tea from Anxi. It provided a foundation for the effective control of pesticides in the process of tea plantations.The result showed that after the mixing of9pesticides, the respective GC retention time of acephate, a-BHC,δ-BHC, fenitrothion, o.p’-DDT, dicofol, permethrin, esfenvalerate, deltamethrin was9.679min,11.908min,12.690min,13.754min,10.220min,23.242min,27.850min,35.238min,35.238min. The corresponding linear equation was y=2129.6x-2172.3, y=143282x+3998.7, y=107347x+5333.7, y=21014x+7574.4, y=31821x+4712.2. y=29216x-6988.2, y=2204.5x+5451.9, y=10068x+14853, y=13924x+21070, as also as the values of R2was among0.9976-1.0000. The spiked recoveries analysis in mixture of different pesticides showed that the recovery rates was among90.4%-107.7%, and the standard deviation were among0.5%-5.7%.On the basis of the testing method and current limits of pesticide residues in tea, the residue assay result of9pesticides in50tea samples showed that11samples had one pesticide overstandard,10samples had two pesticides overstandard,1samples had three pesticides overstandard, none samples had more than three pesticides overstandard, and the pesticides content of28samples were understandard. The unqualified rate of single pesticides indicated that acephate was12%, a-BHC was20%,δ-BHC was20%, fenitrothion was16%, o.p’-DDT was2%, dicofol was0%, permethrin was0%, esfenvalerate was0%, deltamethrin was0%. So. the pesticide residue in tea is still more serious.