Product Overview

Potassium Metabisulphite 95% Extra Pure (CAS No. 16731-55-8) is an inorganic sulphur(IV) salt that produces bisulphite/sulphite species when dissolved in water. These S(IV) species are reducing and oxygen-sensitive, enabling metabisulphite to consume oxidising agents and participate in nucleophilic addition and reductive chemistry. Exposure to air can progressively oxidise sulphur(IV) species toward sulphate, which is important when preserving reagent activity.

The Extra Pure grade is suitable for routine reductive work, preparative chemistry and general laboratory reagent preparation.

Typical Applications

• Reducing reagent in general preparative chemistry.
• Quenching of compatible oxidising reagents after laboratory reactions.
• Preparation of bisulphite/sulphite-containing reaction media.
• Carbonyl bisulphite-addition chemistry and related separations or transformations.
• Oxygen-consuming and reductive treatment of suitable laboratory solutions.
• Dechlorination and reduction studies in laboratory-scale aqueous systems.

Common Synonyms

• Potassium metabisulfite
• Potassium pyrosulphite
• Potassium pyrosulfite
• Dipotassium disulphite
• Dipotassium disulfite
• Pyrosulphurous acid dipotassium salt

Storage Conditions

Store tightly closed and protect from humid air and prolonged atmospheric exposure because sulphur(IV) material can lose reducing activity through oxidation and related compositional change. Minimise exposure after opening and prevent contamination by oxidising materials.