Method for fast detection of residual sulfur dioxide in food

Abstract

The invention discloses a method for fast detection of residual sulfur dioxide in food. The method comprises the following steps: extracting: taking 1 part by weight of sample, placing into a container, simultaneously adding 0.1-10 parts by weight of carbonate, bicarbonate or sodium borohydride and other gas-producing tablet substances and 0.05-10 parts by weight of defoaming agent, and then adding a reaction reagent acid, wherein the adding amount is as follows: the ratio of sample g / reagent volume ml=1: (10-50); distilling under a boiling situation, and collecting sulfur dioxide gas produced by distillation by utilizing 2-10ml of alkaline solution, wherein the adding amount is as follows: the ratio of sample g / alkaline solution volume ml=1: (2-10); forming a collected solution; detecting: taking the collected solution, placing into a glass detection pool, then adding metal nano-sol and an inorganic salt flocculant, uniformly mixing, and then placing into a portable Raman spectrometer detection room for detection. The method disclosed by the invention has the advantages of short detection time, capability of realizing fast screening of large-batch samples, high accuracy and no occurrence of false positive phenomena.

Description

technical field [0001] The invention relates to the field of food detection, in particular to a detection method for sulfur dioxide in food. Background technique [0002] Sulfur dioxide is a colorless gas with a pungent odor in a normal state. It is poisonous and easily soluble in water. After dissolving, it reacts chemically with water to form sulfurous acid. Sulfur dioxide and sulfite have bleaching properties. They react with colored substances to form colorless compounds. Sulfur dioxide is commonly used in industry to bleach paper pulp, wool, silk, straw hats, etc.; however, some unscrupulous traders use sulfurous acid and its salts and Sulfur dioxide produced by sulfur combustion has the functions of bleaching, decolorization, antisepsis, and anti-oxidation, and is illegally abused in food processing to whiten and antiseptic food. Sulfur dioxide and its derivatives will have adverse effects on various systems, organs and tissues of the human body. After sulfur dioxide...

AI Technical Summary

Problems solved by technology

Sulfur dioxide and sulfite have bleaching properties. They react with colored substances to form colorless compounds. Sulfur dioxide is commonly used in industry to bleach paper pulp, wool, silk, straw hats, etc.; however, some unscrupulous traders use sulfurous acid and its salts and The bleaching, decolorization, anti-corrosion, anti-oxidation and other effects of sulfur dioxide generated by sulfur combustion are illegally abused in food processing to whiten and anti-corrosion food

Both of these methods require complex pretreatment of the sample, and the measurement time is long, which requires professional and technical personnel to complete in the laboratory.

In addition, the sodium tetrachloromercury absorption solution used by the former is a highly toxic reagent, and the amount used is large, which is likely to cause mercury pollution to the environment inside and outside the laboratory, which is not conducive to the rapid on-site screening of sulfur dioxide content in food; while the latter uses iodine standard solution The standard product arsenic trioxide (commonly known as arsenic) is required for calibration, which is highly toxic and dangerous, and the color change of the titration end point is not obvious, and the system error is large, so it is not conducive to the on-site rapid screening of sulfur dioxide content in food

[0004] Other detection methods include gas chromatography, ion chromatography, chemiluminescence, electrochemical methods, etc., but these methods require complex pretreatment of samples, require professionals to use special instruments for testing, and the test takes a long time , it is difficult to popularize to some regulatory departments to realize on-site rapid detection

At present, there are also rapid detection kits for SO2 on the market. The principle is that sulfur dioxide in food reacts with a chromogenic agent to generate colored compounds. The visual colorimetric analysis method is used. detection and other advantages, but this method is prone to false positives, low accuracy, and low detection sensitivity

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