Measurement method for fluxapyroxad residue in vegetables and fruits

Abstract

The invention discloses a method for determining the residual amount of flufenapyroxamide in vegetables and fruits. Acetonitrile or an acetonitrile solution containing 1% acetic acid is used to homogeneously extract the residual flufenapyroxamide in the sample, and the extract is treated with ethylenediamine-N - Propylsilane (PSA) and Octadecylsilane bonded phase (C 18 ) after dispersion and purification of the matrix, gas chromatography-negative chemical ion source-mass spectrometry (GC-NCI-MS) detection, a calibration standard working curve was established using a blank matrix solution without the pesticide to be tested, and the external standard method was used for quantification. The average recovery rate of this method is 87.9%-108.1%, the average relative standard deviation (RSD) is 4.7%-8.5%, and the detection limit is lower than 1.59μg / kg. The advantages of quantitative accuracy. It can meet the technical requirements of the United States, the European Union, Japan and other countries for corresponding product safety testing, and provide strong technical support for ensuring the food safety of our people and the healthy development of foreign export trade.

Description

technical field [0001] The invention relates to a method for determining the residual amount of flufenapyroxamide in vegetables and fruits, more specifically, it uses gas chromatography-negative chemical ion source-mass spectrometry (GC-NCI-MS) to qualitatively and quantitatively determine the residual amount of flufenapyroxamide in vegetables and fruits. The invention discloses a method for the content of flufenapyroxamide, which belongs to the technical field of determination of pesticide residues. Background technique [0002] Fluxapyroxad is a succinate dehydrogenase inhibitor fungicide developed by BASF. Chemical name: 3-difluoromethyl-1-methyl-N-(3',4',5'-trifluorobiphenyl-2-yl)-1H-pyrazole-4-carboxamide; molecular formula: C18H12F5N3O ; Relative molecular mass: 381.3; Melting point: 157°C; Relative density: 1.42. Solubility in solvents (g / L, 20°C): acetone > 250, acetonitrile 168, ethyl acetate 123, methanol 53.4, toluene 20.0. The chemical structural formula of...

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, but so far there is no report on the GC-NCI-MS detection method of flufenapyroxamide residues in food and agricultural products. Fyclostrobin is an electronegative compound, and 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 flupyroxad residues in grains and animal-derived foods

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