Sodium Metabisulfite

• Sodium metabisulfite is an inorganic salt compound, soluble in water and glycerol, slightly soluble in alcohol, and its solubility in water increases with increasing temperature.

• Chemical Formula: Na₂S₂O₅
• Molecular Weight: 190.10
• CAS No.: 7681-57-4
• Appearance: White or slightly yellow crystalline powder or small crystals with a strong sulfur dioxide odor.

Product Detail

Technical Indicators

Items	Standard	Analytical result
Na2S2O5	97.0% min	97.30%
SO2	65%min	65.60%
Sodium sulfite	1%max	<1%
Sodium Sulfate	1%max	0.72%
Fe	0.0005%max	0.00%
Chloride	0.5%max	<0.5%
Heavy metals(Pb)	0.0005% max	<0.0005%
As	0.0001% max	<0.0001%
Water insolubles	0.05%	0.00%
PH Value	4.0-5.0	4.6
Conclusion	The goods up to the requirement of standard

Product Use Description

Sodium metabisulfite (Na₂S₂O₅) is mainly used as a preservative, bleaching agent, and antioxidant in the food industry, as well as a reducing agent, dechlorinating agent, and synthetic intermediate in the chemical, printing and dyeing, and pharmaceutical industries.

Food Industry

Used for preservation, antibacterial properties, prevention of browning (color protection), and loosening (e.g., improving biscuit dough) in preserved fruits, candied fruits, dried vegetables, wine, and white sugar. It is safe to use within national standard limits.

Chemical and Pharmaceutical Industries

Used in the production of sodium dithionite (Sodium hydrosulfite), sulfonamide drugs (e.g., sulfadiazine), vanillin, and chloroform purification; used as an antioxidant to stabilize drug components in injectables.

Printing and Dyeing & Leather Making

Used as a dechlorinating agent after bleaching cotton fabrics, a scouring aid, and a softening agent for deliming leather.

Industrial Applications

Oilfield water injection deoxygenation, electroplating wastewater treatment (reduction of hexavalent chromium), mineral processing (inhibiting mineral floatability), and as a component of photographic fixing solutions.

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