Rapid detection method for water-soluble azo dyes in foods

Abstract

The invention provides a rapid detection method for water-soluble azo dyes in foods. The method comprises the steps of (A), sample extraction; (B), polyamide column concentration and purification; (C), elution of pigments; and (D) qualitative detection. According to the rapid detection method, the rapid screening can be timely and effectively carried out on suspected samples, the method is independent of large-scale instruments and equipments, and lawbreakers can be harshly attacked within the shortest time; and besides, the rapid detection method further has the advantages of short detection time, wide applicable range, high detection accuracy, low detection limit, strong anti-interference capacity and the like.

Description

technical field [0001] The invention relates to the field of food safety detection, in particular to a rapid detection method for water-soluble azo dyes in food. Background technique [0002] Domestically approved pigments mainly include natural pigments and synthetic pigments. Among them, the allowed synthetic pigments include low-toxic azo dyes such as carmine, sunset yellow, and amaranth. Reasonable use of food coloring can make food bright and attractive, and stimulate appetite. However, driven by profit, unscrupulous traders abuse synthetic pigments beyond the scope and even illegally use industrial dyes, causing outbreaks of "Sudan Red" and "dyed steamed buns" and other food safety incidents. At present, there are few rapid detection methods for banned and restricted azo dyes and industrial pigments in food at home and abroad, and many foods that use substandard pigments cannot be killed in the production field. Therefore, it is necessary to establish relevant rapid d...

AI Technical Summary

Problems solved by technology

Therefore, in the application process of this method, there may be false positives and misjudgments based solely on the color of the organic layer before and after treatment, which is not conducive to accurately determining whether the sample uses fat-soluble pigments illegally.

[0008] For detection method 2), in the existing technology (patent application No. 20081002995.9), the amount of polyamide or wool used in the adsorption sheet is small, and the amount of pigment on the plate is limited, which is not conducive to enrichment when the content of synthetic pigment in the sample is low and color development, prone to missed judgments

After the pigment is enriched by the adsorption sheet, some natural pigments with strong adsorption capacity (such as curcumin, monascus red, etc.) cannot be completely removed by pure water alone, and will eventually affect the result of positive determination

[0009] For detection method 3), in the existing technology (patent application No. 201110350255.7), the operation process of rapid color test of textiles is complicated, and because the diazotization-coupling reaction is generally carried out at 1-5°C, at room temperature Nitrous acid and diazotization intermediates are easy to decompose, which is not conducive to the subsequent color reaction, and there may be missed judgments

[0010] Therefore, the existing detection methods have the disadvantages of being easily interfered by interfering substances, poor accuracy, complex operation, long detection time, and the need for complex analytical instruments, and cannot be quickly detected for water-soluble azo dyes.

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