Method for determining residual quantity of dazomet and metabolite methyl isothiocyanate thereof in plant-derived food

Abstract

The invention relates to a method for measuring the residual quantity of dazomet and metabolite methyl isothiocyanate thereof in plant-derived food, which comprises the following steps: pretreatment: crushing a sample to be measured, adding ethyl acetate, performing vortex oscillation for extraction, and then centrifuging; sucking the supernate, adding ethylenediamine-N-propyl silanized silica gel, graphitized carbon black, C18 and anhydrous magnesium sulfate for purification, carrying out vortex mixing, centrifuging, taking the supernate, and filtering a membrane to obtain an extracting solution; detecting the extracting solution by a gas chromatography-triple quadrupole mass spectrometer, and quantifying by a matrix matching external standard method. According to the method, the linear relation of the target compound in the range of 0.01-0.10 mg / kg is good, and correlation coefficients are all larger than 0.99. The average recovery rate of a blank sample at low, medium and high addition levels is 81.5%-109.4%, the relative standard deviation (n = 6) is 2.8%-9.0%, and the limit of quantitation of the method is 0.01 mg / kg. The method is simple, rapid and sensitive to operate, and can meet the detection requirements of dazomet and metabolite methyl isothiocyanate thereof in plant-derived food.

Description

technical field [0001] The invention relates to a detection technology for pesticide residues, in particular to a method for determining the residues of dacetamone and its metabolite methyl isothiocyanate in plant-derived foods. Background technique [0002] Dipyron, the chemical name is 3,5-dimethyl-1,3,5-thiadiazine-2-thione, is a stable crystalline solid at room temperature, has a fumigation effect, and is often used to control soil fungi, kill It can effectively kill root-knot nematodes, soil pests, weeds and various soil-borne diseases, so as to obtain clean and healthy soil; it is an ideal soil treatment agent to replace methyl bromide. In acidic soils, it slowly decomposes to release methyl isothiocyanate, methylamine, carbon disulfide and hydrogen sulfide, which diffuse upward through spaces in the soil, killing organisms that come into contact with it. When agricultural products are planted in the soil treated with cotton wool, residues in food will be caused, whic...

AI Technical Summary

Problems solved by technology

[0004] In the existing relevant literatures, the detection methods of damaron and its metabolite methyl isothiocyanate all use different pretreatment methods and different instruments and equipment to detect damaron and methyl isothiocyanate respectively, such as Feng Yizhi et al. Use liquid chromatography to determine the cotton wool in tomato and soil, and use gas chromatography-mass spectrometry to measure methyl isothiocyanate in tomato and soil. Two pretreatment methods are required, and two instruments and equipment are used; Xu Feng et al. established an ultra-efficient Liquid chromatography-tandem mass spectrometry and gas chromatography for the determination of methyl isothiocyanate in strawberries require two pretreatment methods, and the use of equipment is also two; in actual operation, the related methods are complicated to operate and require more cost Manpower and material resources are not conducive to daily promotion and use

Images