Sodium metabisulfite is white or yellow crystalline powder or small crystal, with a strong SO2 odor, soluble in water, the aqueous solution is acidic, when contacted with strong acid, SO2 is released to form corresponding salts, and it is oxidized to Na2S2O6 when placed in the air for a long time. Therefore, the product cannot be stored for a long time. Above 150 degrees Celsius, SO2 is decomposed.
Function:
1.It is used as bleaching agent, mordant, reducing agent, rubber coagulant, and also used in organic synthesis, pharmacy, spices, etc
2.It is used as chromatographic analysis reagent, antiseptic and reducing agent, dye and pharmaceutical industry.
3.Sodium pyrosulfite has stronger reducibility than sulfite, and its effect is similar to that of sodium sulfite. Our country stipulates that it can be used for candied fruits, biscuits, sugar, crystal sugar, malt sugar, candy, glucose, liquid glucose, bamboo shoots, mushrooms and canned mushrooms, with the maximum use amount of 0.45g/kg. The residue (calculated by SO2) of candied fruits, bamboo shoots, mushrooms and canned mushrooms, grapes and blackcurrant concentrated juice is less than 0.05/kg; The residue of biscuits, sugar, vermicelli and other varieties is less than 0.1g/kg; The residual amount of liquid glucose shall not exceed 0.2g/kg.
4.Food industry is used as bleach, antiseptic, loose agent, antioxidant, color fixative and fresh-keeping agent.
5.The pharmaceutical industry is used to produce phenylsulfone and benzaldehyde. The rubber industry is used as a coagulant. The printing and dyeing industry is used as a dechlorination agent after bleaching of cotton cloth and a cotton scouring auxiliary. The leather industry is used for leather treatment, which can make the leather soft, plump, tough, waterproof, folding resistant, wear-resistant and other properties. Chemical industry is used to produce hydroxyvanillin, hydroxylamine hydrochloride, etc. The photosensitive industry is used as developer, etc.
6.For analysis. preservative. Reducing agent. Antioxidant
INSPECTION RESULT | |||
ITEMS | UNIT | STANDARD | RESULT |
Na2S2O5 | % | 97, MIN | 97.60 |
SO2 | % | 65,MIN | 65.75 |
Iron (Fe) | PPM | 30,MAX | 19 |
Heavy Metals as Pb | PPM | 5, MAX | 3 |
As | PPM | 1, MAX | 0.8 |
PH value | 4-4.6 | 4.5 |