Study On Rapid Analysis Of Multipesticide Residue And The Fate Of Typical Pesticide In Environment

Pesticides, as a kind of significant agricultural materials, play a great role in pushing the yield and quality of agricultural products. However, it has been long-term use that will cause environmental pollution and damage. In recent years, with the increase of health consciousness of human beings, the problem of pesticide residues have been paid more and more attention now. Therefore, strengthening the monitor of pesiticide residue and study of the fate of typical pesiticide in environment will avoid unnessaray loss of agriculture, and all of this has important significant theory and practice significance in environment protection and human health.In this study, we developed a rapid analysis of multi-pesticide residue for analyzing common pesticides including eighteen organochlorine, twenty-one organophosphate and ten sulfonylurea herbicides respectively in fish, vegetables and water, soil and rice plant. And azoxystrobin as a typical pesticide example, we analyzed the fate of azoxystrobin distribution and degradation in simulation and actual paddy field-fish pond system. The results can supply base data and valuable experience to the scientific evaluating typical pesiticide environment safety.The research work contents and results are as followings:(1) Establishment residue analytical methods for organochlorine pesticides in fishThis work developed a miniaturized matrix solid phase dispersion method (MSPD) for the analysis of organochlorine pesticides in fish samples (Carassius auratus) by gas chromatography with electron capture detection (ECD). Using matrices curve for quantitative analysis, the correlation coefficient of standard curve is above0.994. The average recoveries and relative standard deviations were73.0%to116.8%,1.6%to13.6%respectively. The limits of detection were less than3.5μg/kg. The miniaturized procedure was easier, faster, less time consuming than the conventional MSPD procedure and solid phase exaction (SPE).(2) Establishment residue analytical methods for organophosphate in vegetables This paper established the method for disposable pipette extraction for the analysis of organophosphate by gas chromatography-mass spectrometry in Chinese vegetables. Using matrices curve for quantitative analysis, the correlation coefficient of standard curve is above0.995. It has shown good recovery (80.5～105.3%) for various levels of spiked organophosphate(Log P>2). The relative standard deviations were less than13.0%. The limits of detection were were in the range of0.4to5.9μg/kg, the limits of quantification below17.7μg/kg. The method could meet the requirement for detecting trace pesticide residues.(3) Multi-residue method for the determination of sulfonylurea herbicides in three environmental matrices:paddy field water, paddy field plant and paddy field soilIn this study, we proposed a sensitive and very fast analytical method for screening10sulfonylurea herbicides in paddy field water, paddy field plant and paddy field soil. Using matrices curve for quantitative analysis, the correlation coefficient of standard curve is above0.995except tribenuron-methyl. Under the optimized conditions, the average recovery for each analyte was in the range of86.2to114.1%for paddy field water,77.6to116.1%for paddy field plant and84.2to115.7%for paddy soil, with RSD lower than14.3%in all cases. The limits of detections are partly0.002to0.069ng/mL,0.011to0.356μg/g and0.024to0.427μg/g. The method is sensitive, accurate, easy and simple.(4) Study on the fate of typical pesticide in the environmentThis paper studied systematically simulation and actual of paddy field-pond ecosystem trial, and analyzed the transformation and degration of azoxystrobin in paddy field soil, water, pond water and pond sendiment after used in the paddy field. In the simulation paddy field-pond ecosystem, the concentration of paddy field water was0.102mg/L after azoxystrobin applied in paddy field, and then it quickly entered paddy field soil, whose concentration was highest level as24hours of adsorption, being stable after that; the peak of pond water and pond sediment was respectively0.003mg/L and0.06mg/kg at24hours after application.In the actual rice field-pond ecosystem, the concentration of paddy field water was0.087mg/L after azoxystrobin applied in paddy field, and then it quickly entered paddy field soil, whose concentration was highest level as24hours of adsorption, being gradually decrease after that; the peak of pond water and pond sediment was respectively0.011mg/L and0.194mg/kg at24hours after application. The results showed that the degradation of azoxystrobin in simulation and actual rice field-pond ecosystem was rapid, which is not esay to remain in the ecosystem.