What component does sodium metabisulfite account for in chemical products

Sodium metabisulfite is white or yellow crystalline powder or small crystal, with strong SO2 smell, specific gravity 1.4, soluble in water, aqueous solution is acidic, SO2 is released upon contact with strong acid to generate corresponding salts, and if left in the air for a long time, it will oxidize Into Na2S2O6, so the product cannot last for long. Above 150 degrees Celsius, SO2 is decomposed.

Ingredients and composition: Harmful ingredient CAS No., sodium metabisulfite 7681-57-4,

Category: 　Antioxidant.

Content determination

Thiosulfate

Take 1.1g of this product, slowly add 10ml of dilute hydrochloric acid, after dissolution, heat in a water bath for 10 minutes, let cool, transfer to a colorimetric tube, add water to 20ml, if it is cloudy, and sodium thiosulfate titration solution (0.1 mol/L) 0.20ml of the control solution prepared by the same method shall not be more concentrated (0.2%).

Iron salt

Take 1.0g of this product, add 5ml of water and 2ml of hydrochloric acid to dissolve, put it on a water bath and evaporate to dryness, add 15ml of water and 2ml of hydrochloric acid to the residue. After dissolving, add an appropriate amount of bromine test solution to make the solution microscopic yellow, heat to remove excess bromine, let cool , Add water to 25ml, check according to law, and it should not be deeper (0.002%) compared with the control solution made of standard iron solution 2.0ml.

Heavy metals

Take 1.0g of this product, add 10ml of water to dissolve it, add 5ml of hydrochloric acid, put it on a water bath and evaporate to dryness, add 15ml of water to the residue, slowly boil for 2 minutes, filter, add an appropriate amount of bromine test solution to the filtrate to clarify, heat to remove excess bromine , Allow to cool, add 1 drop of phenolphthalein indicator solution and the appropriate amount of ammonia test solution to make the solution appear pink, add 2ml of acetate buffer (pH3.5) and an appropriate amount of water to make 25ml, check according to law, and the content of heavy metals should not exceed one million Twenty.

Arsenic

Take 1.0g of this product, add 4ml of water to dissolve, add 3ml of nitric acid, put it on a water bath and evaporate to dry, add a few milliliters of water to the residue, stir well, filter, wash the filter residue with water, combine the washing liquid with the filtrate, evaporate, add 5ml of hydrochloric acid With 23ml of water, after dissolution, check according to law, it should meet the regulations (0.0002%).

The main purpose

Chemical and pharmaceutical industries

It is used for the production of insurance powder, sulfamethazine, analgin, caprolactam, etc. as well as the purification of chloroform, phenylpropyl sulfone and benzaldehyde. It is used as a fixer ingredient in the photographic industry. The perfume industry is used to produce vanillin. Used as preservative in brewing industry, rubber coagulant and dechlorinating agent after cotton bleaching. Organic intermediates, dyes, and leather are used as reducing agents. Used as electroplating industry, oil field wastewater treatment, and as a mineral processing agent in mines.　

industry

It is used in printing and dyeing, organic synthesis, printing, tanning, pharmaceutical and other departments; used as preservatives, bleaching agents, loosening agents in food processing.

Used as a chemical reagent

(Dyeing and photography, etc.), used as a bleaching agent, mordant, reducing agent, rubber coagulant, also used in organic synthetic pharmaceuticals and perfumes.