Automatic sample pretreatment and detection method for detecting residual of multiple pesticides in tea leaves

Abstract

The invention relates to an automatic sample pretreatment and detection method for detecting the residual of multiple pesticides in tea leaves, and belongs to the technical field of pesticide residual detection. The method comprises the following steps: weighing tea leaf powder, and extracting; filtering the above obtained extraction liquid by using anhydrous sodium sulfate, adding the filtered extraction liquid to the autoinjection bottle of a fully-automatic quantitative concentrator, concentrating until dryness, and dissolving by using acetonitrile; transferring the extraction liquid to the sample bottom of a fully-automatic solid phase extractor, and purifying by adopting a GCB / PSA cartridge; transferring the above obtained eluate to the sample bottle of the fully-automatic quantitative concentrator, concentrating until dryness, and dissolving residues by using a methanol / water solution with the volume ratio of 1:1; and transferring the obtained sample solution to a liquid chromatogram-tandem mass spectrum autoinjection bottle through a 0.22[mu]m organic filter membrane, and carrying out liquid chromatography and mass spectrometry. The sample pretreatment and detection method for detecting the residual of multiple pesticides in tea has the characteristics of high automation program, simple operation and high working efficiency, meets requirements of residual of multiple pesticides in the tea, and is suitable for daily detection of tea quality inspection mechanisms in China.

Description

technical field [0001] The invention belongs to the technical field of pesticide residue detection, and in particular relates to an automatic sample pretreatment and detection method for detection of various pesticide residues in tea. Background technique [0002] The sample pretreatment method for the detection of pesticide residues in tea mainly includes three links: extraction, concentration, and purification. compound, the extract is concentrated to near-dryness by rotary evaporator or nitrogen blowing apparatus, and the organic solvent dissolves the residue to be further purified. Compared with other agricultural products or foods, the components in tea extracts are complex and high in content, which can easily interfere with target pesticides, lead to qualitative and quantitative deviations, and even produce erroneous results. Therefore, the requirements for the purification treatment of tea pesticide residue detection are relatively high, and purification techniques ...

AI Technical Summary

Problems solved by technology

[0003] The main shortcomings of the current sample pretreatment technology for the detection of pesticide residues in tea include: low degree of automation, high labor intensity, complicated operation, long time and low efficiency

However, the accelerated solvent extraction instrument, automatic quantitative concentrator and automatic solid-phase extraction instrument have not been effectively connected in the sample pretreatment methods for the detection of pesticide residues in tea so far. unsolved

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