The Residue And Degradation Of Acetamiprid And Fenitrothion In Tobacco Field And Its Adsorption

In order to study the residues digestion and ecological environment effects that acetamiprid and fenitrothion being used in tobacco field and to determine its ecological behavior and safety, to Guide its scientific and rational use. Added recovery experiment method was established to simultaneously determine the residues of acetamiprid and fenitrothion in tobacco fields. And on this basis, systematically studied 20% aceptamiprid’ fenitronthion EW was applied in soil planted tobacco, fresh tobacco leaves and flue-cured tobacco leaves of tobacco samples.Then put forward 20% aceptamiprid’ fenitronthion EW in the rational use of tobacco fields of science suggestions. In addition, the adsorption of aceptamiprid and fenitrothion and its main factors in six kinds of soil were studied. Moreover to study the different content of charcoal (bamboo charcoal) on insect amidine or fenitrothion adsorption effect in six kinds of soil. The main conclusions in this paper were as follows:(1) An analytical method was established to simultaneously determine the residues of acetamiprid and fenitrothion in tobacco fields by gas chromatography with ECD(electron-capture detector). The average recoveries of this two pesticids varied from 71.36%～106.28% with relative standard deviation of 1.51%～9.20%, when two kinds of pesticides were spiked at 0.05-1.00 mg/kg level in soil and tobacco. The minimum detectable amount of aceptamiprid and fenitrothion was 5.0 × 10-11g, and the minimum residue concentration was 0.05mg/kg in soil planted tobacco, flue-cured tobacco leaves and fresh tobacco leaves. The method in this study is simple and can meet the requirements of analysis. It is suitable for determining the residues of acetamiprid and fenitrothion in tobacco samples.(2) Field experiments were carried out to reveal the residue dynamics and final residue of aceptamiprid and fenitrothion in tobacco field in Changsha and Qingdao after 20% aceptamiprid’ fenitronthion EW was applied. Results showed that the half-lives in soil planted tobacco was 3.32d～11.61 days, and fresh tobacco leaves was 2.35d～6.21days, it means that aceptamiprid and fenitrothion was degradable pesticide. When 20% aceptamiprid’ fenitronthion EW was applied two-three times with the dosage of 300g/ha and 450g/ha in tobacco field, the results show that: after applied 35 days, the residue of aceptamiprid and fenitrothion in flue-cured tobacco leaves was less than 1.3305mg/kg, this residue was less than tentative maximum residue limits value(10.0 mg/kg) of aceptamirid in tobacco leaves (flue-cured tobacco leaves).(3) The absorption time for aceptamiprid and fenitrothion, among one of the six chosen tested soil, was about 24h. This is in line with the isothermal adsorption model and the Freundlich model, and the correlation coefficient is above 0.85. Fenitrothion adsorption capacity of the order in six texted soil was:JiLin black soil>GuangXi red soil>HuNan chao soil>HeNan chao soil>HuNan red soil>ShanDong brown soil; Aceptamiprid adsorption capacity of the order in six texted soil was:GuangXi red soil>HuNan red soil>HuNan chao soil>JiLin black soil> ShanDong brown soil>HeNan chao soil.(4) Adding different amount of acrtivated carbon, the adsorption capacity of fenitrothion is increased in six tested soil, and aceptamiprid is down.