Subject sulfites

In rabbits and human subjects, sulfite (metabolite of sulfur dioxide) that reaches the plasma has been shown to form S-sulfonate products (R-S-S03-) by reacting with the disulfide bonds of proteins (Gunnison and Palmes 1974). Gunnison and Palmes (1974) exposed human subjects continuously to 0.3, 1.0, 3.0, 4.2, or 6.0 ppm sulfur dioxide for up to 12 h, determined that plasma sulfonate concentrations had a positive correlation with air concentrations of sulfur dioxide. Although the biochemical significance of these S-sulfonate products is not currently understood, their formation represents a biochemical alteration (Costa and Amdur 1996). 

Sulfites and related compounds have been the subject of much controversy. It has been shown that these chemicals may cause serious allergic reactions in sensitive individuals. In the United States, sulfite-containing foods must be labeled as such, and sulfites ate prohibited in areas such as salad bats where labeling is inappropriate. 

Like other polysulfur compounds, the sulfanes are subject to degradation if treated with strong nucleophiles like aqueous sulfite, arsenite or cyanide ... 

Unreacted free sulfur can be determined to ISO 7269 1995 — Rubber — Determination of free sulfur. Three methods for the determination of free sulfur in vulcanized rubber are detailed two versions of the copper spiral method and the sodium sulfite method. The copper spiral methods are also applicable, subject to limitations, to unvulcanised rubber. The technique of DSC can detect non-reacted rubber curatives such as residual peroxides. 

The remaining half of the sulfite solution is subjected to the same treatment, and the total ether extract, after drying, is evaporated on a water bath. The residue is then distilled under reduced pressure, yielding 200-215 g. of almost colorless citral which boils at 84-85°/2 mm. (93-95°/5 mm.). 

The total iodine procedure is claimed to be relatively free from interference by foreign ions. The iodate procedure is subject to interference by bromate and sulfite ions. This method is claimed to be capable of determining down to 0.1 ig iodine in the presence of 500 mg chloride ion and 5 mg of bromide ion. 

A flash photolysis method has been developed that prepares the MoVI-Fe11 state and thus allows the rate constants k3 and k 3 to be measured. Solutions containing 5-deazariboflavin, semicarbazide, and sulfite oxidase are subjected to 555 nm flash photolysis. The deazariboflavin is excited to a triplet state, which is then reduced by semicarbazide to form the 5-deazariboflavin semiquinone radical. This radical is then rapidly oxidized back to its parent species through the one-electron reduction of sulfite oxidase. 

TAYLOR S L, BUSH R K, SELNER J C, NORDLEE J A, WIENER M B, HOLDEN K, KOEPKE J w and busse w w (1988), Sensitivity to sulfited foods among sulfite-sensitive subjects with asthma , J Allergy Clin Immunol, 81(6), 1159-67. 

Wood chips are processed in mild chemical liquor and subjected to mechanical refining using disc refiners. Semichemical pulping liquors have variable composition ranging from sodium hydroxide alone, alkaline sulfite (sodium sulfite - - sodium carbonate), mixtures of sodium hydroxide and sodium carbonate, to Kraft green or white liquors [3]. Sodium sulfite/ sodium carbonate liquor is most commonly used and the pulp product obtained thereafter is referred to as neutral sulfite semichemical (NSSC) pulp. 

Leaf A ground in polyvinylpyrrolidone medium without sodium sulfite. Leaf B ground in same medium with sodium sulfite. Control leaves not exposed to ozone or subjected to dark. Dark period is 18 hr following exposure to ozone. 

A -Glycosylation of sulfites 55a and 55b using silylated thymine in dry conditions at 125 °C yielded a mixture of 2 -0-silylated and 2 -hydroxy-5-methyluridine derivatives 56a and 56b, and 57a and 57b, respectively (Scheme 2). Subjecting these mixtures to desilylation conditions tetrabutylammonium fluoride, methanol (TBAF, MeOH), gave 2 -hydroxy-5-methyluridine derivatives 57a and 57b. Additionally, epimer 58 was produced as a minor product (13.5%) of N-glycosylation of 5-0-benzoylated compound 55b <2005JME4276>. 

A solution of sulfite ester 6 (I g, 4.7 mmol) and 8M NH3 in MeOH (100 mL) was stirred for 24 h at rt. The mixture was evaporated to dryness and the residue dissolved in the minimum amount of MeOH and subjected to column chromatography (silica gel, CHCl3/MeOH 9 1). Removal of the solvent and recrystallization (hot MeOH) gave a colorless solid yield 0.3 g (38%) mp 148 150 C. 

F. Sodium Bisulfite Addition Product Formation The red color of aminochrome solutions is rapidly discharged by the addition of sodium bisulfite with the formation of pale-yellow fluorescent solutions. The reactions of adrenochrome with sulfites and bisulfites have been the subject of several previous reports.12, 102.109.118,119.123,128,148.182.155. 158,173-177 Although it was originally... 

Many countries do not allow use of S02 or sulfite salts on meats, fish, piocessed meat and fish products, 01 flesh fruits and vegetables. Where permitted, sulfite is helpful in eliminating black spot formation in shrimp. End-use application of sulfite related compounds as. for example, to prevent discoloration of leafy vegetables on salad bars, is now subject to regulation in the United States. 

Sulfite, S032-, is a bivalent polyanion. It occurs in boiler feed water that is treated with sulfite for controlling dissolved oxygen. It also occurs in waters subjected to S02 treatment for dechlorination purpose. Sulfite forms sulfurus acid, H2S03, which gradually oxidizes to sulfuric acid. Excess sulfite in boiler waters can cause corrosion. Sulfite is toxic to aquatic life. 

The combination of radiolabeled sulfide and the bimane-HPLC method is particularly powerful because one of the main obstacles to the use of labeled sulfide is, that aside from radioactive decay, the compound is subject to rapid oxidation in the presence of air. The breakdown products of chemical sulfide oxidation are the same as those of biological oxidation. Previously it has been impossible to check routinely the purity of the purchased isotope and its subsequent purity during a series of experiments. It is our experience that newly purchased sodium sulfide sometimes contains up to 10% thiosulfate as well as traces of sulfite and sulfate (Figure 2), and that the sulfide once hydrated readily oxidizes if stored in a normal refrigerator. 

Sulfidic sulfur, S > and sulfite are important contaminants in coal conversion process streams. The voltammetric methods described in the preceding section of this paper and the thermochemical techniques based on Equations 9-15 above provide alternative options for the determination of sulfides and of SOf in coal conversion process streams. Cross checking of results with the aid of both types of methods must necessarily provide dependable information. The electroanalytical and enthalpimetric methods are conceptually so diverse that they cannot conceivably be subject to similar systematic errors. Their combined use is effectively nfail-safe.M... 

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