The Rules Of Pesticide Residue And The Exploration Of REE Pollution Causes Of Anxi Oolong Tea

This thesis was studied on 10 kinds of pesticide residues and present situation of REE content of four seasons,mao cha samples(summer,shuji,autumn in 2009 and spring in 2010),which collected from five areas(Huqiu,Xiping,Jingu,Gande and Xianghua) of Anxi county. And discussed the REE pollution causes from tea processing, soil factors and exogenous spraying REE foliar fertilization.The results of the study showed that:1.The sequence of the rate of pesticide residues,detection in four seasons was:Summer﹥Autumn﹥Shuji﹥Spring.The sequence of the rate of pesticide residues,detection in five areas was:Gande﹥Jingu﹥Xiping﹥Xianghua﹥Huqiu.(1) Octachlorodipropyl ether was not detected in all tea samples. dichloro-diphenyl-trichloroethane was not detected in shuji and autumn,s samples. Fenvalerate was not detected in spring,s samples. The contents of Triazophos and Bifenthrin in shuji, autumn and spring,s samples were significant higher than summer. The contents of Fenpropathrin Cypermethrin in autumn and spring,s samples were significant higher than summer and shuji.(2) In five areas,Organophosphorus pesticide and Organochlorine pesticides were detected very little,Deltamethrin pesticide were commonly used。In summer,the residues of Cypermethrin were highest in Jingu area and deltamethrin were highest in Gande area。In autumn and spring,the residues of dicofol were highest in Xiping area。In spring,the residues of Bifenthrin were highest in Jingu area。The others were no significant difference.2 .The REE content of four seasons,samples in five areas,Jingu area were highest and the average vaule were 8.971±2.011,8.087±4.020,10.189±4.233 and 9.312±4.512 mg/kg.And compared with the other four areas,the differences reached a significant level.In spring,the content of REE in Xianghua area was more significant difference than Xiping and Huqiu.The sequence of the contents was:Jingu﹥Xianghua﹥Gande﹥Xiping﹥Huqiu.3 .The contents of REE had changes in four seasons.The contents of REE in Huqiu area were concentrated on 1～3mg/kg and the average vaule was 2.108±0.874mg/kg;compared with four seasons,the differences reached a significant level.The contents of REE in Xiping area were concentrated on2-3.5mg/kg and the average vaule was 2.371±0.654 mg/kg;compared with summer and shuji,the differences reached a significant level.The contents of REE in Jingu area were concentrated on 6-14mg/kg and the average vaule was 9.132±3.595 mg/kg;compared with four seasons,the contents were were no significant difference.The contents of REE in Gande area were concentrated on 1-4mg/kg and the average vaule was 2.872±1.374mg/kg;compared with four seasons,the contents were were no significant difference.The contents of REE in Xianghua area were concentrated on 3-5mg/kg and the average vaule was3.967±1.584mg/kg;compared with four seasons,the contents were were no significant difference.4 .The experiments to find the REE pollution causes showed tea processing was not the cause,but the total content of REE in soil and exogenous spraying REE foliar fertilization were the causes leading to REE pollution.