Sales Manager in Charges of Potassium Metabisulfite;
Angela Zhu
Email:chem1@top-pharmchem.com;
Sales Manager
TOP Pharm Chemical
Potassium metabisulfite, K2S2O5, also known as potassium pyrosulfite, is a white crystalline powder with a pungent sulfur odour. The main use for the chemical is as an antioxidant or chemical sterilant. It is a disulfite and is chemically very similar to sodium metabisulfite, with which it is sometimes used interchangeably. Potassium metabisulfite is generally preferred out of the two as it does not contribute sodium to the diet.
It is used as a food additive, also known as E224.It is restricted in use and may cause allergic reactions in some sensitive persons.Potassium is an inhibitor of the polyphenol oxidase enzyme
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Item
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Standard
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Test Results
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Appearance
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White or almost white powder, or colourless crystals.
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Complies
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Solubility
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Freely soluble in water, slightly soluble in ethanol (96%).
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Complies
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Identification
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A. pH (see Tests).
B. To 5 mL of solution S (see Tests), add 0.5 mL of 0.05 M iodine. The mixture is colourless and gives reaction (a) of sulfates .
C. Solution S gives reaction (a) of potassium.
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Complies
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Solution Appearance
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Solution S is clear and colourless
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Complies
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K2S2O5
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≥97%
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97.8%
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SO2
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≥56.0%
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56.8%
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K2S2O3
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≤0.1%
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0.001%
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Na
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≤2%
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0.075%
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Cl
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≤0.05%
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0.001%
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pH
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3.0 to 4.5 for solution S.
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4.3
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Heavy metals
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≤10 ppm
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Complies
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As
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≤1 ppm
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Complies
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Cu
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≤1 ppm
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0.1
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Fe
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≤5 ppm
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3.3
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Hg
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≤0.1 ppm
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Complies
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Pb
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≤1 ppm
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Complies
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Se
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≤1 ppm
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Complies
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Zn
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≤1 ppm
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0.3
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Storage
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In an airtight container, protected from light.
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Complies
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