Effects Of β-Cyclodextrin's Derivatives On Solubilization Photodegradtion And Biotoxicity Of Two Pesticides

According to the reported methods, Methyl- 3 -cyclodextrin and hydropropyl- 3 -cyclodextrin products were produced by the methyl reaction in the alkatroplic solvents. The infrared spectrum (IR)and the X-ray diffraction (XRD) were used to identify methyl-3-cyclodextrin and hydropropyl-3 -cyclodextrin. The experimental results demonstrated that the products were similar to those of American medicine company, which shows the quality of methyl- 3 -cyclodextrin and hydropropyl- 3 -cyclodextrin products are the same as the American standards.The influence of methyl- 3 -cyclodextrin and hydropropyl- 3 -cyclodextrin on inclusion of methyl parathion and carbofuran was investigated. The results indicated that both methyl- 3 -cyclodextrin and hydropropyl- 3 -cyclodextrin products can increase the solubility of pesticides. The solubilization concentration of methyl parathion and carbofuran increased by 21.91,17.92 and 4.01,3.87 times, respectively, in the presence of 20g/L methyl- 3 -cyclodextrin and hydropropyl- 3 -cyclodextrin (25 癈 ), indicating that the derivatives enhanced solubilization more effectively than 3-cyclodextrin.3 -cyclodextrin and its derivatives were able to catalyze the photodegradation of the pollutants. The results showed that methyl-3 -cyclodextrin and hydropropyl- 3 -cyclodextrin accelerated the photol yt ic rates of methyl parathion. The T,.2 shortened greatly from 103. 9 to 18. 19h and 15. 16h in the presence of 6g/L methyl-3-cyclodextrin and hydropropyl- 3 -cyclodextrin, indicating positively photosensive degradation. The photosensive rates of methyl- 3 -cyclodextrin and hydropropyl- 3 -cyclodextrin on photodegradation of methyl parathion depended on the concentration of methyl- 3 -cyclodextrin and hydropropyl-3-cyclodextrin and reactive time.The inclusion of organic pollutants by 3 -cyclodextrin and its derivatives greatly influenced the biotoxicity of the pollutants. Theexperimental results demonstrated that LC50 of methyl parathion increased,ranging from 5. 92mg/L to 12. 53mg/L and 12. 34mg/L (96h), respectively. It means that methyl- 0 -cyclodextrin and hydropropyl- (3 -cyclodextrin greatly lessened the biotoxicity of methyl parathion more than twice (96h).Due to the their apolar cavuty, methyl- 3 -cyclodextrin and hydropropyl-P-cyclodextrin are able to include pesticides and increase the solubility of pesticides in the aqueous solution, accelerated the photolytic rates, and lessened the biotoxicity. So methyl- (3 -cyclodextrin and hydropropyl-P-cyclodextrin have the potential to be widely used in environmental science in the future.