Method for purifying vegetable containing pyrethroid pesticide residue by using graphene

Abstract

The invention discloses a method for purifying vegetable containing pyrethroid pesticide residue by using grapheme in the field of pesticide residue analysis of vegetables. The method comprises the following steps of (1) extraction, i.e. weighing proper amount of pre-crushed homogenized vegetable sample containing pyrethroid pesticide, adding an extraction solvent into the sample, and performing vortex or vibration extraction; (2) separation, i.e. adding sodium chloride to perform salt precipitation, and performing centrifugal separation; (3) purification, i.e. taking the supernate, adding the grapheme into the supernate, and after the grapheme is fully contacted with the supernate, adding sodium chloride to perform centrifugal separation; and (4) detection, i.e. taking the supernate, adding anhydrous sodium sulfate or magnesium sulfate anhydrous into the supernate, and after the excessive water content is removed, performing gas chromatogram. The grapheme serves as a purifying material, and compared with graphitized carbon black and N-propyl ethylenediamine bonded silica gel which are conventionally used in a laboratory, the grapheme is low in using amount, strong in absorption ability and low in cost; the method is simple, quick and convenient to perform; and the accuracy is high, and the recovery rate is between 96.0 percent and 99.6 percent.

Description

technical field [0001] The invention belongs to the field of analysis of pesticide residues in vegetables, and in particular relates to a method for purifying vegetables containing pyrethroid pesticide residues by using graphene. Background technique [0002] Graphene is a new carbon material in which carbon atoms are tightly packed into a single-layer two-dimensional honeycomb lattice structure. The thickness of this graphite crystal film is only 0.335nm, which is only 1 / 200,000 of hair. The basic unit of several carbonaceous materials (such as zero-dimensional fullerenes, one-dimensional carbon nanotubes, and three-dimensional graphite). The theoretical specific surface area of ​​graphene material is as high as 2600m 2 / g, with outstanding thermal conductivity (3000W / (m K)) and mechanical properties (1060GPa), as well as high-speed electron mobility at room temperature (15000cm 3 / (V·s)). In addition, its special structure makes it have a series of properties such as ha...

AI Technical Summary

Problems solved by technology

The purification adsorbents used in the analysis of pesticide residues include graphitized carbon black, N-propylethylenediamine bonded silica gel, etc. The amount of these adsorbents is usually tens of milligrams or more, and the cost is relatively high

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