A method for determining pesticide residues in tea

A technology for pesticide residues and tea, applied in the field of analysis and detection, can solve the problems of low triazine pesticide residues, unsatisfactory pesticide extraction effect, and high detection cost, and achieves improved extraction efficiency and detection accuracy, excellent purification and extraction characteristics, The effect of reducing sample loss

Active Publication Date: 2017-08-22
湖南山水检测有限公司
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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

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  • A method for determining pesticide residues in tea
  • A method for determining pesticide residues in tea

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Embodiment Construction

[0019] In order to further explain the detection of triazine pesticide residues in tea leaves by gas chromatography-mass spectrometry, a more detailed description will be given below with examples.

[0020] 1. Test part

[0021] (1) Sample pretreatment: take 2g of tea leaves and grind them, dissolve them in 100ml of deionized water, and use 6ml of acetonitrile-acetone solution with a volume ratio of 2:3 for ultrasonic extraction. The ultrasonic time is 15 minutes, and then centrifuged for 8 minutes. At 10000r / mmin, the extract was obtained.

[0022] (2) Stir bar solid-phase extraction: immerse a stir bar coated with cellulose-graphene coating into the above extract, and stir for 15 min by magnetic stirring in a closed environment to perform solid-phase extraction.

[0023] Among them, the preparation method of the cellulose-graphene coating is as follows: through esterification, use cellulose to modify the surface of graphene to obtain, and the prepared cellulose-modified gra...

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Abstract

The invention relates to a method for measuring pesticide residue in tea leaves. The method comprises the following steps: (1) pre-treating a sample, namely after smashing the tea leaves, dissolving with water, using an acetonitrile-acetone-methanol solution for performing ultrasonic extraction, centrifuging, and then acquiring an extract liquor; (2) using a stirring rod for performing solid-phase extraction, namely soaking the stirring rod coated with a polymer-graphene coating into the extract liquor, thereby performing the solid-phase extraction; and (3) performing gaseous phase chromatography-mass spectrometric detection, wherein the triazine pesticide residue is confirmed as the pesticide residue and a cellulose-graphene coating serves as the polymer-graphene coating on the stirring rod. According to the method provided by the invention, the detection for the pesticide residue in the tea leaves can be efficiently and conveniently realized.

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...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01N30/88G01N30/06
Inventor 王欣汲送花李泠玥石俊龙
Owner 湖南山水检测有限公司
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