Gas chromatography method for simultaneously measuring four benzoic acid herbicides in grain

Abstract

The invention relates to a method for analyzing and detecting trace harmful substances, in particular to a gas chromatography method for simultaneously measuring the residue of trace dicamba, 2,3,6-Trichlorobenzoic acid, amoben, and chlorthal in grain. The method comprises the following steps: ultrasonically extracting a target in a sample with a 10% water-acetone solution of pH=9; enriching a target compound in an extracting solution by using a novel adsorbent, benzsulfonate-magnesium-aluminum hydrotalcite calcined product; dissolving the adsorbent by using a hydrochloric acid solution to achieve complete elution of the target; efficiently extracting the compound with a small dose of organic solvent; and rapidly analyzing and measuring by gas chromatography method after derivatization. According to the gas chromatography method for simultaneously measuring the residue of trace dicamba, 2,3,6-Trichlorobenzoic acid, amoben, and chlorthal in grain, rapid and efficient adsorption of the target object is achieved by a novel adsorbent adopted in the method in a dispersed solid phase extraction mode, and a large amount of adsorption time can be saved compared with the gel permeation chromatography method and solid phase extraction method; the complete desorption of the target object can be achieved by using the acid to dissolve the adsorbent; and the method is only suitable for a small amount of organic solvent extraction, and has significant safety, environmental protection advantages and economic advantages.

Description

technical field [0001] The invention relates to a method for analyzing and detecting harmful trace substances, in particular to a gas chromatographic method for simultaneously measuring trace amounts of dicamba, bacamba, mebazone and chlorphthalic acid residues in grains. Background technique [0002] Herbicides are important substances in agricultural production and play a major role in killing harmful weeds and increasing the yield of agricultural products. However, with the widespread use of various herbicides, the problems of herbicide abuse and residues have become increasingly prominent. Among them, benzoic acid herbicides are one of the most important ones. Currently, the types sold and used in the market include dicamba, fenfoam, mebafen, and chlorphthalic acid. They all belong to the low-to-medium toxicity herbicides. Skin contact can cause poisoning, clinical symptoms vary. [0003] Benzoic acid herbicides are phytohormone herbicides, which have systemic conductio...

AI Technical Summary

Problems solved by technology

[0007] In order to overcome the time-consuming and inefficient use of gel permeation chromatography in the pretreatment of the detection of benzoic acid herbicide residues in the existing standard methods, the need to consume a large amount of organic solvents, not suitable for large-throughput sample screening, and the use of solid phase in literature methods The extraction column is time-consuming and inefficient, and the types of solid-phase extraction columns are limited. The technical problem to be solved by the present invention is to provide a new adsorbent-based dispersive solid-phase extraction for fast adsorption, suitable for trace amounts of dicamba, grass Gas Chromatography for Simultaneous Determination of Residues of Trimethoprim, Metrazil and Chlorophthalic Acid

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