Study On The Effect Of Chiral Pesticide Toxin Fluorine And Phosphorus On The Activity Of Aquatic Animal Earthworms And Its Selective Degradation In Earthworms

Chiral pesticide dufulin is a new anti-viral agent of α-aminophosphonate with good antiviral activity.At present,there are few reports on the environmental behavior of dufulin the aquatic environment.In this study,taking tubifex as a model organism and dufulin as the research object,the stereoselectivity of the degradation of dufulin enantiomers in tubifex and different effects of Rac-dufulin and enantiomers on biochemical index parameters of tubifex were studied.The main research contents and conclusions are as follows:1.Soluble protein content,MDA content,and activities of antioxidant enzymes(SOD,CAT,GST,GR)were measured in tubifex by spiked-water treatment,to investigate different effects of Rac-dufulin and enantiomers on biochemical markers in tubifex.The results showed that Rac-dufulin and enantiomers had no significant effects on total protein content and GR activity in tubifex,but significant difference of SOD,CAT,GST activities and MDA content were observed.Effect of R enantiomer on SOD activity was significantly different from that of S enantiomer and Rac-dufulin,there’s significant difference of R enantiomer,S enantiomer and Rac-dufulin on CAT and GST activities,and effect of the Rac-dufulin on the MDA content is less than enantiomers.2.The dose-effect linear relationship was investigated between the changes of biochemical parameters in tubifex and the exposure dose of dufulin.The results showed that there was no significant dose-effect linear relationship between MDA content,SOD,CAT activity in tubifex and exposure concentration of dufulin.There was no significant dose-effect linear relationship between GST activity changes and exposure doses of S enantiomer and R enantiomer,but GST activity elevated with increasing exposure doses of Rac-dufulin after 14 days of exposure.3.The analysis methods of dufulin enantiomers in tubifex,soil and overlying water samples were established and verified by Superchiral S-OD chiral column and LC-MS/MS.The results showed that average recoveries of S enantiomer and R enantiomer in three matrixes ranged from 82.31% to 108.58%,the RSD values were between 0.50% and 12.51%,and the LOQ values were between 0.01 and 0.02 mg/kg,LOD values were ranged from 0.003 to 0.006 mg/kg,which satisfied the requirements of pesticide residue analysis methods for accuracy and precision.4.The experiment of enrichment-degradation of spiked-water treatment and spiked-soil treatment were carried out for studing the degradation behavior of dufulin enantiomers in tubifex.It was found that dufulin enantiomers were quickly eliminated in tubifex,and the degradation rate of S enantiomer is faster than the R enantiomer.Through the study on the distribution of dufulin enantiomers in the system of spiked-soil treatment,it was found that concentrations of dufulin enantiomers in underlying soil were significantly higher than concentration in overlying water,the bioturbation of tubifex caused dufulin enantiomers in the underlying soil to diffuse into the overlying water.Compared with initial concentrations of dufulin enantiomers in tubifex,concentrations of dufulin enantiomers released into underlying soil and overlying water was relatively small.