The Study On Indirect Competitive Enzyme-Linked Immunosorbent Assay For Esfenvalerate

The haptens of2-(4-Chloro-phenyl)-3-methyl-butyric acid carboxy-(3-phenoxy-phenyl)-methyl ester (Efva),2-(4-Chloro-phenyl)-3-methyl-butyric acid (3-carbox y-propylcarbamoyl)-(3-phenoxy-phenyl)-methyl ester (Efvb)4-[2-(4-Chloro-phenyl)-3-methyl-butyrylamino]-butyric acid (Efab) were synthesized. The haptens were conjugated with ovalbumin (OVA) as coating antigens by mixed anhydride met hod and conjugated with bovine serumin (BSA) asimmunogen by active ester method. The antibody against esfenvalerate was generated by immunizing the N ew Zealand rabbits. The heterologous assays were more sensitive comparing wi th homologous assays.After the optimization of pH values, inonic strengths, concentrations of met hanol, the forty percent methanol,0.4mol/L Na+and pH7.4, were determined to optimum assay condition of the method one for esfenvalerate. Standard compe titive curve of optimized ic-ELISA for esfenvalerate was developed. The IC50f or esfenvalerate was3.16mg/L, and the lowest detection limit IC10was0.0053m g/L. Fenpropathrin, deltamethrin, cyhalothrin, cypermethrin and the acid of esfe nvalerate metabolites tested did not cross-react significantly in this assay. Tap water, river water and soil samples were spiked with esfenvalerate at0.1、1、1Omg/L (mg/kg). The average recoveries were in the range of82.27%-108.21%,83.12%-109.19%,72.04-91.23%, and the Coefficient of Variations were3.80%-6.20%,2.73%-7.71%,3.11%-4.69%respectively. It reaches the requirement s of residuesanalysis.After the optimization of pH values, inonic strengths, concentrations of met hanol, the forty percent methanol,0.4mol/L Na+and pH8.4, were determined t o optimum assay condition of the method two for esfenvalerate. Standard comp etitive curve of optimized ic-ELISA for esfenvalerate was developed. The IC50for esfenvalerate was2.24mg/L, and the lowest detection limit IC10was0.0052mg/L. Fenpropathrin, deltamethrin, cyhalothrin, cypermethrin tested did not cros s-react significantly in this assay. Tap water, river water and soil samples were spiked with esfenvalerate at0.1,1,10mg/L (mg/kg). The average recoveries were in the range of88.50%-107.69%,85.38%-108.40%,78.30-85.88%and t he Coefficient of variations were2.67%-3.42%,5.31%-9.74%,3.91%-5.34%res pectively. It reaches the requirements of residues analysis.