Method for determining quantity of diquat or paraquat residual in food

Abstract

The invention relates to a method for determining the quantity of diquat or paraquat residual in food. The method comprises the steps of pretreating a sample: firstly extracting the diquat or the paraquat in the food sample by using a methanol aqueous solution; purifying the extract by using C18 and PSA (Primary Secondary Amine) dispersive solid-phase extraction agents; and finally by combining ahigh performance liquid chromatography with a quadrupole time-of-flight mass spectrometry, realizing qualitative and quantitative determination of the diquat or the paraquat residual in the food through the accurate mass number of compound ions. The method disclosed by the invention has the beneficial effects that the matrix interference in the detection of the diquat or the paraquat residual in the food is effectively reduced; the recovery rate of the diquat or the paraquat can be up to 80.8%-97.3%; the relative standard deviation is 3.5%-7.8%; the limit of quantification is 10mug / kg; the method has the advantages of being simple and convenient to operate, fast, accurate, high in sensitivity and good in repeatability; and the method is a supplement and an improvement on a conventional QuEChERS method.

Description

technical field [0001] The invention belongs to the technical field of determination of pesticide residues, in particular to a method for determination of diquat or paraquat residues in food. Background technique [0002] During the planting of fruits, vegetables, grains and other crops, farmland weeds have an important impact on crop yield and quality. The use of herbicides in agricultural production not only saves a lot of heavy weeding manual labor and mechanical weeding operations, but more importantly, reduces the loss of agricultural product yield and quality caused by weeds, and obtains considerable economic benefits. However, with people's attention to food safety issues, the hazards of herbicide residues to human health have also attracted much attention. For example, diquat or paraquat (diquat), which is a moderately toxic herbicide, is a non-selective herbicide of organic heterocycles. Widely used in potatoes, cotton, soybeans, corn, sorghum, flax, sunflower and...

AI Technical Summary

Problems solved by technology

[0005] Another object of the present invention is to provide a sample pretreatment method to make up for the deficiency that the existing internationally recognized QuEChERS method cannot be used for the detection of diquat or paraquat residues