Study on Enzyme-linked Immunosorbent Assay for Chlorpyrifos in Environment

Abstract

【Objective】Chlorpyrifos is widely used and has good stability, and its residue has been detected in the environmental medium in many areas. In order to monitor the residues of chlorpyrifos in soil, water and other environmental substrates, and to ensure the quality and safety of environment, enzyme-linked immunosorbent assay (ELISA) was used to detect chlorpyrifos rapidly in the environment.【Method】Based on the principle of specific binding of antigen and antibody, an indirect competitive ELISA was established to detect chlorpyrifos in the environment. The test conditions were optimized, and the sensitivity, cross-reaction and effect of organic solvents on the antibody were studied.【Result】Under the optimal conditions, the logarithm of chlorpyrifos concentration was linearly related to the absorbance value, the regression equationwas B/B0=-24.87 logC + 97.55 and the correlation coefficient (R2) was over 0.99. The IC50 of chlorpyrifos was 81.65 ng/mL, and the detection limit IC20 was 5.1 μg/L. The method was validated by selecting appropriate pretreatment methods according to different substrates. The recovery rates of chlorpyrifos ranged from 70% to 115% and the relative standard deviation was less than 11%. The relative standard deviation of precision was less than 10%. The accuracy of the method was verified by comparison with the gas chromatography. The prepared reagents shall not be stored for more than 6 months. The detection effects were not affected by reagents at 4 ℃ and -20 ℃ within 180 days.【Conclusion】With certain specificity, stability and precision, the established indirect enzyme-linked immunosorbent assay can be used for rapid and flexible detection of chlorpyrifos residues in different types of soil and water samples.

Keywords

• chlorpyrifos
• water
• soil
• enzyme-linked immunosorbent assay (elisa)
• pesticide residue