| With the organochlorine pesticides are disabled, carbamate pesticides’usage has increased year by year. More and more such pesticides are discharged into the environment, pollute the soil, threaten the health of human and living things. The research of such pesticides’ biological effects and degradation characteristics in the soil not only contributes to their impact on non-target organism, but also help to understand their migration and transformation in the soil. And it can provide basic data for the evaluation of the compound’s effect on the environment and improve the selectivity of such pesticides. The experiment took the Chinese tropical soil Hainan brick red soil and Eisenia foetida (non-target organisms in the soil) as the research objects. It Compared different concentrations of carbosulfan technical and preparations’ degradation dynamics and the influence on earthworms survival in the soil; different concentrations of carbosulfan raw materials’ degradation dynamics and the influence on earthworms survival in the sterilized and natural soil; different concentrations of Carbofuran’s dynamic changes and the influence on earthworms survival in the soil. The main conclusions are as follows:A method for the determination of carbofuran residues in the soil by HPLC with post-column derivatization system and fluorescence detector was developed. The sample was extracted with acetonitrile and cleaned-up by amido solid-phase extraction column with methanol-dichloromethane(1:99, V/V)as the eluent. the limit of detection of carbofuran was0.01mg/kg. The average recoveries of carbofuran from the soil ranged from89.1%to102.9%, with RSD of1.5%～4.3%.The average conversion rate of carbosulfan preparations in the soil is greater than the technical. The efficiency of carbosulfan preparations converted to Carbofuran in the soil is far greater than carbosulfan technical in the low concentration group(42.74,85.47,170.94mg/kg). But In the high concentration group(512.82mg/kg) the two have no significant difference. carbosulfan technical and preparations have a significant inhibitory effect on the growth and activity of the earthworm, and can damage the skin structure of the earthworm. The mortality of earthworms in the soil which was contaminated by carbosulfan preparations is higher than the technical, showing that the toxicity of pesticide formulations on earthworms in the soil is higher than the technical. As Carbofuran concentration in the soil increasing, the earthworm mortality is increasing, and the conversion efficiency of carbosulfan is gradually decreasing.The efficiency of carbosulfan translated into Carbofuran in natural soil is significantly higher than in sterilized soil, and with the concentration of carbosulfan in soil increases, such cases are more obvious. In the same concentration the mortality of earthworms in sterilized soil is much higher than natural soil, showing that the toxicity of carbosulfan on earthworm and other biological in sterilized soil is greater than natural soil. The efficiency of carbosulfan converted to Carbofuran in the soil is not only related to the concentration in the soil,but also related to the biomass in the soil closely.The degradation rate of Carbofuran in the soil is slow. When the concentrations of Carbofuran in the soil are3.410,5.437,7.790,10.928and12.770,14.801mg/kg, its half-life is respectively13.72,28.29,23.18,16.74,18.99and17.03d.As the concentration increased half-life decreases gradually. Carbofuran has a significant inhibitory effect on the growth and activity of the earthworm, and can damage the skin structure of the earthworm. Earthworm’s activity can promote the degradation of Carbofuran. High concentrations of Carbofuran can significantly inhibit the survival of the earthworm. Earthworm mortality and the Carbofuran concentration in the soil is positively correlated, and earthworm mortality and rate of disappearance of Carbofuran in soil is negatively correlated. |
