Determining method of Pyrifluquinazon residual quantity

Abstract

The invention relates to a determining method of Pyrifluquinazon residual quantity. The method comprises the following steps: homogeneously extracting residual Pyrifluquinazon in a sample by using acetonitrile or an acetonitrile solution containing 1% acetic acid; after dispersed purification of an extracting liquid by using an ethidene diamine-N-propyl silane (PSA) and octadecyl silane bonded phase (C18) matrix, detecting by gas chromatography-negative chemical ionization-chromatography (GC-NCI-MS); and establishing a corrected standard curve by using a blank substrate solution without to-be-detected pesticides, and quantifying by an external standard method. According to the method provided by the invention, the average recovery rate is 88.7-96.1%, the average relative standard deviation (RSD) is 4.7-6.9% and the detection limit is lower than 0.81 microg / kg. The determining method has the advantages of being simple and convenient to operate, quick, high in sensitivity, good in repeatability and accurate to qualify and quantify and can satisfy the technical requirement on safety detection of corresponding products in countries such as Korea, Japan and European Union, and thus a powerful technical support for guaranteeing the food safety of people in China and healthy development of foreign export trade is provided.

Description

technical field [0001] The present invention relates to a method for determining residual Pyrifluquinazon content, more specifically, a method for qualitatively and quantitatively determining residual Pyrifluquinazon content in vegetables and fruits by gas chromatography-negative chemical ion source-mass spectrometry (GC-NCI-MS), which belongs to pesticides Determination of residues technical field. Background technique [0002] Pyrifluquinazon is a new quinazoline insecticide with a bisamide structure invented by Japan Pesticide Company and jointly developed by Japan Combination Chemical Company. It is mainly used to control aphids, whiteflies and mealybugs on vegetables, fruit trees and tea. , leafhoppers, thrips and other piercing-sucking pests. The chemical name is 1-acetyl-3,4-dihydro-3-[(3-pyridylmethyl)amino]-6-[1,2,2,2-tetrafluoro-1-(trifluoromethyl ) ethyl]-2-(1H)-quinazolinone, the CAS accession number is 337458-27-2, and the structural formula is: [0003] ...

AI Technical Summary

Problems solved by technology

Now various testing institutions and enterprises have purchased gas chromatography-mass spectrometers (GC-MS), and are generally equipped with negative chemical ion sources (NCI). Now many types of pesticides contain electronegative groups, organochlorines and pseudo Pyrethrin pesticide molecules mostly contain strong electronegative groups such as -F, -Cl, -Br or -COO-; organophosphorus pesticide molecules mostly contain =S, -OR, -P, -O-, -Cl, or -P=O and other electronegative groups; and most of the new pesticides developed in recent years contain -F groups. Therefore, the use of GC-NCI-MS can facilitate the multi-residue analysis of various pesticides. Compared with MS, it can obtain better anti-interference ability, lower sensitivity and better selectivity. Pyrifluquinazon is an electronegative compound, but so far there is no GC-NCI-MS detection of Pyrifluquinazon residues in vegetables and fruits Therefore, it is of great significance to establish a gas chromatography-negative chemical ion source-mass spectrometry (GC-NCI-MS) detection method for the qualitative and quantitative analysis of Pyrifluquinazon residues in vegetables and fruits

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