an enzyme electrode was developed using the enzyme sulfite oxidase (ec1.8.3.1) immobilized onto pig intestine. hydrogen peroxide produced was monitored amperometrically. all experimental parameters such as ph, temperature, buffer constituent concentration, were thoroughly investigated and optimized when appropriate. the response to sulfite concentration was linear in the range 5.2´10-6 to 1.02´...

The redox properties of sulfite ion has been examind using cyclic voltammetry in acetonitrile solvent at the surface of gold, pelatin and glassy carbon electrodes. It has bben found tha, sulfite ion exhibits two electron oxidation peak with EC’ mechanism. A novel chemically modified electrode containing Prussian blue complex and multi wall carbon nanotubes (MWCNs) was achieved on the surface of...

Acidithiobacillus ferrooxidans strain D3-2, which has a high copper bioleaching activity, was isolated from a low-grade sulfide ore dump in Chile. The amounts of Cu(2+) solubilized from 1% chalcopyrite (CuFeS(2)) concentrate medium (pH 2.5) by A. ferrooxidans strains D3-2, D3-6, and ATCC 23270 and 33020 were 1360, 1080, 650, and 600 mg x l(-1) x 30 d(-1). The iron oxidase activities of D3-2, D3...

A method is described for determining sulfite in dried garlic. Garlic is extracted with an HCl solution to inhibit the formation of allicin, which interferes with the determination of sulfite. After cleanup of the extract on a C18 solid-phase extraction column, sulfite is converted to hydroxymethylsulfonate (HMS) by adding formaldehyde and heating to 50 degrees C. HMS is determined by reversed-...

Two fluorescent probes, m-PSP and p-PSP , for sulfite and/or sulfide were constructed by connecting a pyridinium ion to a coumarin fluorophore through an α,β-unsaturated ketone. The presence of the pyridinium salt promoted the nucleophilic addition of sulfite and sulfide to the α,β-unsaturated ketone, which could be visualized by dramatic changes in the solution's color and fluorescence intensi...

BACKGROUND Sodium metabisulfite is added to a commercial propofol emulsion as an antimicrobial agent. The sulfite ion (SO3(-2)) is capable of undergoing a number of reactions, including autooxidation and the promotion of lipid peroxidation. This study evaluated sulfite reactivity in propofol emulsions by determining thiobarbituric acid reacting substances (TBARS), sulfite depletion, and emulsio...

A new type of sulfite oxidase which utilizes ferric ion (Fe3+) as an electron acceptor was found in iron-grown Thiobacillus ferrooxidans. It was localized in the plasma membrane of the bacterium and had a pH optimum at 6.0. Under aerobic conditions, 1 mol of sulfite was oxidized by the enzyme to produce 1 mol of sulfate. Under anaerobic conditions in the presence of Fe3+, sulfite was oxidized b...

Rapid separation and determination of mixtures of L-ascorbic acid, nitrite, sulfite, oxalate, iodide and thiosulfate by conventional ion chromatography is often difficult due to incomplete separation of L-ascorbic acid and nitrite from the water peak when using eluents giving short elution times for iodide and thiosulfate. Separation of the six species within about 15 min has been achieved by i...

Acetic acid is one of the major inhibitors of spent sulfite liquor (SSL) fermentation for ethanol production. The objective of this study was to remove acetic acid from hardwood SSL using anion exchange resin in order to achieve effective fermentation with Pichia stipitis CBS6054. Lignosulfonate, as well as sulfate and sulfite ions in the SSL hindered the removal of acetic acid by anion exchang...