A method for determining pesticide residues in tea

Abstract

The invention relates to a method for measuring pesticide residues in tea. The method comprises the following steps that firstly, samples are pretreated, wherein tea are smashed, dissolved with water and then subjected to ultrasonic extraction through an acetonitrile-acetone-methanol solution, and extract liquor is obtained after centrifugation; secondly, solid-phase extraction is carried out through a stirring rod, wherein the stirring rod coated with a polymer-graphene coating is steeped into the extract liquor for solid-phase extraction; thirdly, gas-phase chromatography-mass spectrometric detection is carried out, wherein the pesticide residues are triazine pesticide residues; the polymer-graphene coating on the stirring rod is specifically a chitosan-graphene coating. By means of the method, the pesticide residues in tea can be efficiently, easily and conveniently detected.

Description

technical field [0001] The invention belongs to the technical field of analysis and detection, and in particular relates to a method for checking the residual amount of triazine pesticides in tea by using gas chromatography-mass spectrometry. Background technique [0002] Triazine pesticides are organic heterocyclic compounds, which have both bactericidal and plant growth-regulating effects. They have become a class of high-efficiency fungicides with a wide range of applications, flexible use methods, good control effects, and the most potential for development and application. However, its irrational use will pose a potential health threat to humans and pollute the ecological environment, and its residues in food have attracted more and more attention. [0003] Due to the low amount of triazine pesticide residues in tea leaves, traditional liquid-liquid extraction or SPE cartridges are usually used for extraction. Various solvents are used in the whole process, and the oper...

AI Technical Summary

Problems solved by technology

However, its unreasonable use will cause potential health threats to humans and pollute the ecological environment, and its residues in food have attracted more and more attention.

[0003] Due to the low amount of triazine pesticide residues in tea leaves, traditional liquid-liquid extraction or SPE cartridges are usually used for extraction. Various solvents are used in the whole process, and the operation steps are cumbersome, resulting in a large loss of the components to be tested. The extraction efficiency Not high, affecting the final detection precision and accuracy

[0004] At present, although some researchers introduce graphene into the detection process of triazine residues, they use magnetic graphene nanoparticles for extraction. On the one hand, the dispersion of nanoparticles is poor, and the extraction effect of pesticides is not ideal. The operation steps are complicated, the subsequent cleaning process is difficult, and the recovery rate of magnetic particles is low, which leads to high detection costs and cannot be widely used