Method for detecting pesticide residues in sulfur-containing vegetables by enzyme inhibition method

Abstract

The invention discloses a method for detecting pesticide residues in sulfur-containing vegetables by an enzyme inhibition method. The method comprises the following steps of 1, preparing a standard solution, 2, preparing a sample, 3, testing control groups through the processes of adding a buffer solution into a beaker, adding dropwisely acetate or sodium hydroxide into the beaker, adjusting a pH value of the mixed solution to a pH value of 9, adding an enzyme solution and a color-developing agent into the mixed solution with a pH value of 9, shaking up, standing at a temperature of 37 DEG C for 15 minutes, adding a substrate solution into the mixed solution treated by the previous step, shaking up, and detecting an absorbance variation value delta A0 of the mixed solution undergoing a reaction at wavelength of 410 nanometers for 3 minutes by a spectrometer, 4, adding sulfur-containing vegetable sample extract into a beaker, carrying out processes same as the processes of the step 3, and detecting an absorbance variation value delta A1 of a vegetable sample mixed solution undergoing a reaction at wavelength of 410 nanometers for 3 minutes by a spectrometer, and 5, calculating an enzyme inhibition percentage according to a formula of an enzyme inhibition percentage=[(delta A0-delta A1) / delta A0]*100, wherein when the calculated enzyme inhibition percentage is great than or equal to 50%, it is shown that there are pesticide residues in the detected sulfur-containing vegetable. The method eliminates the interference of sulfides in a sulfur-containing vegetable on pesticide residue detection through adjustment of a pH value of a vegetable sample solution, can rapidly, simply and accurately detect a pesticide residue ratio of a sulfur-containing vegetable, has a low cost, and is suitable for on-site detection.

Description

technical field [0001] The invention relates to a method for detecting residues of organic phosphorus and carbamate pesticides, in particular to a method for detecting residues of organic phosphorus and carbamate pesticides in sulfur-containing vegetables by an enzyme inhibition method. Background technique [0002] With the improvement of people's living standards, the problem of pesticide residues in vegetables and fruits has aroused widespread concern. Organophosphorus and carbamate insecticides are widely used, accounting for more than 70% of the amount of insecticides used. At present, the detection methods of organophosphorus and carbamate pesticide residues in my country mainly include gas chromatography, thin layer chromatography and enzyme inhibition method. Chromatography is accurate in quantification and high in sensitivity, but the analytical instruments are expensive, the measurement time is long, and it requires professional and technical personnel to operate,...

AI Technical Summary

Problems solved by technology

This method is simpler than the heating method, but the evaporation of the sample liquid during the microwave heating process will cause inaccurate results