Study Of Ten Pesticides Including Imidacloprid On Pesticide Residue Analysis

Residue of pesticides found in agriculture products, drinking water and environmental exposure has raised much concern from the general public in recent years. In order to protect persons' healthy, the maximum residue levels (MRL) in food were constituted by WHO/FAO-CAC. It is important to exploit simply, fast, efficient pre-treatment technologies for samples and high sensitive, high selective multi-pesticide detections technologies based on pesticide and veterinary drug residues in food and the requirement for international trade on food.The thesis includes three parts:In chapter I : The application of micellar liquid chromatography on pesticide residues Under the condition of 0.06mol/LSDS solution, ten pesticides, including imidacloprid thiophanate-methyl cartap carbofuran ricylazole diuron isoprocarb metalaxyl teufenozide mefenacet, were separated and determined. The HPLC conditions were: 0.06 mol/L SDS and 10%acetonitrile(v/v) were used as liquid phase; the flow rate is 0.6ml/min; the detection wave-lenghth was 220nm. The linear relation of ten kinds of pesticides in the range from 0.05 to 60mg/L(r≥ 0.9997) with the detection limit from 0.0017 to 0.0253mg/L. Then we studied the optimal conditions for extracting water by cloud-point extraction. It were added 5% tween-20, 5% NaCl , heating five minutes at 90℃ and then centrifuge at 3500rpm for 5 minutes. The methods had been applied to determine the recoveries of ten pesticides in tap water.In chapter II: The study of sodium nitroprusside by single-sweep oscillopolarography The electrochemical behavior of sodium nitroprusside(SNP)-Cu( II) was studied by using cyclic voltammetry, linear scanning voltammetry and bulk electrolysis with coulometry. In a base solution of 0.2 mol/L Clark-Bruce at pH3.0, both of SNP and SNP-Cu(II) system all produced sensitive reduction peak at -0.47V(vs.SCE).But the sensitivity of SNP-Cu(II) system was 100 times higher than SNP. The linear relation holds between the peak current and SNP concentration in the range from 2.0×10^-7 to 4.0×10^-5mol/L(r=0.9997) with the detection limit of 1.0×10^-7mol/L. The relative standard...