Sulfite


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Related to Sulfite: hyposulfite, sulfite oxidase

sulfite

[′səl‚fīt]
(inorganic chemistry)
M2SO3 A salt of sulfurous acid, for example, sodium sulfite, Na2SO3.

Sulfite

 

any of several salts of sulfurous acid, H2SO3. Two series of sulfites exist: the normal sulfites, with the general formula M2SO3, and the acid sulfites, or hydrogen sulfites, with the general formula MHSO3, where M is a monovalent metal. Normal sulfites—with the exception of the sulfites of alkali metals and ammonium sulfite—are sparingly soluble in water. They dissolve in the presence of SO2. Among the acid sulfites, only those of the alkali metals have been isolated in the free state.

Sulfites in aqueous solution are characterized by oxidation to sulfates and reduction to the thiosulfates, M2S2O3. Sulfites are obtained by the reaction of SO2 with hydroxides or carbonates of the corresponding metals in an aqueous medium. The hydrogen sulfites are more frequently used, and their applications are in the textile industry for dyeing and printing (KHSO3 and NaHSO3), in the paper industry for the production of wood pulp [Ca(HSO3)2], in photography, and in organic synthesis.

References in periodicals archive ?
Scientific data on sulfites and what happens to them inside the body are limited.
Joe Krebs, Director of Protein Chemistry for Bioo Scientific: "The MaxSignal Sulfite Assay Kit is the latest addition to Bioo Scientific's existing line of enzymatic assays for the detection of additives and adulteration in food and feed samples.
When a sulfite reacts with another molecule and becomes part of its structure it no longer takes part in the equilibrium reaction and it is called bound.
Sulfite oxidase has cofactors of molybdenum, pyridoxine, cobalamine, and other influences.
To aid in your label reading, there are six names used for sulfites: sulfur dioxide, sodium sulfite, sodium bisulfite, potassium bisulfite, sodium metabisulfite, and potassium metabisulfite.
It may have naturally occurring sulfites (some can be a byproduct of fermentation), but the total level must be less than 20 parts per million.
A similar drop in viscosity is measured when DMS, dimethyl sulfite, and DMC are added to the epoxy resin also.
While trace amounts of sulfites occur naturally in wines during the fermentation process, most producers add more, later in the winemaking process, to prolong shelf life.
The USDA allows up to 100 ppm total sulfite concentration for wines labeled "made with organically grown grapes.
Although naturally occurring sulfites are found in almost all wines, sulfite preservatives are known to cause allergic reactions.
Complicating the issue is the fact that, although commercial sulfite is an additive, sulfite naturally results from yeast fermentation during wine production.