Determination Of Multiple Pesticide Residues In Fruits And Vegetables By Matrix Solid Phase Dispersion Extraction-High Performance Liquid Chromatography

Organophosphorus and carbamate are the most widely used pesticides in the crops planting, these pesticides will lead to residues in agricultural products(including fruits and vegetables) after being used, and then pollute the environment, and pose a serious threat to people's health. With the requirements of food quality and the requirements of relevant laws and regulations, it is important to establish a fast, convenient, economical and practical method for trace analysis. In this paper, follow the principle of green economy and practical application, a method using matrix solid-phase dispersion extraction- high performance liquid chromatography has been developed for the determination of organophosphorus and carbamate pesticide residues. The primary coverage of this thesis as follows:(1)Three organophosphorus pesticide( Dimethoate, Phoxim, Chlorpyrifos) residues in fruits were extracted and detected by using matrix solid-phase dispersion-reverse phase high performance liquid chromatography(HPLC). The optimum pretreatment conditions were obtained in experiments and are as follows: 0.6g Florisil as the best extraction adsorbent, the mass ratio of sample to dispersant at 1:3, 10 mL eluent ethyl acetate as eluting solvent, 0.05 g PSA as decontaminant. Under optimized experimental conditions, limits of detection ranged from 0.01 to 0.07 ?g/g, the linear range of determination was 0.2~10 ?g/g and the correlation coefficient was 0.9991 ~ 0.9996. When the developed method was applied to the fruit samples, average recoveries of 80.5% ~ 107.3% were achieved and corresponding RSD values were within 1.8% ~ 11.6%. This experiment only spends about half an hour among the analysis. The method is simple and has advantages of simple operation, short processing time and low solvent consumption, and is suitable for the analysis of trace organic phosphorus pesticide residues in fruits and vegetables.(2)Three carbamate pesticide(Methomyl,Carbofuran, Carbaryl) residues in fruits were extracted and detected by using matrix solid-phase dispersion-reverse phase high performance liquid chromatography(HPLC). The optimum pretreatment conditions were obtained in experiments and are as follows: Florisil as the best extraction adsorbent, the mass ratio of sample to dispersant at 1:4,a mixture of 3:7(v/v) acetone: methylene chloride as eluting solvent, 10 m L eluent volume. Under optimized experimental conditions, limits of detection ranged from 0.02 to 0.62 ?g/g, the linear range of determination was 0.2~40 ?g/g and the correlation coefficient was 0.9957 ~ 0.9957. When the developed method was applied to the fruit samples, average recoveries of 80.4% ~ 116.5% were achieved and corresponding RSD values were within 0.7% ~ 8.0%. The method is simple with less solvent consumption and the test results are satisfactory.