Showing papers on "Sodium sulfite published in 1990"

Inhibition of browning of sulfur amino acids. 2. Fruit juices and protein-containing foods

Abstract: Enzymatic and nonenzymatic browning reactions may adversely affect the quality, nutritional value, and safety of foods. A need therefore exists to develop methods to control such reactions in a variety of foods. Reflectance measurements were used to compare the relative effectiveness of a series of compounds in inhibiting browning in freshly prepared and commercial fruit juices including apple, grape, grapefruit, orange, and pineapple juices. The potential inhibitors tested include ascorbic acid, a commercial formulation called Sporix, sodium sulfite, N-acetyl-L-cysteine, L-cysteine, and reduced glutathione. For comparison, related studies were also carried out with several protein-containing foods such as casein, barley flour, soy flour, nonfat dry milk, and the commercial infant formula Isomil. The results revealed that under certain conditions SH-containing N-acetyl-L-cysteine and the tripeptide reduced glutathione may be as effective as sodium sulfite in preventing both enzymatic and nonenzymatic browning. The unique electronic and nucleophilic properties of sulfhydryl compounds that enable them to act as inhibitors of both enzymatic and nonenzymatic browning are discussed. These sulfur amino acids merit further study to assess their potential for preventing long-term food browning under practical storage and processing conditions.

Effect of EDTA on the photocatalytic activities and flatband potentials of cadmium sulfide and cadmium selenide

Abstract: Photocatalyzed hydrogen evolution on Pt-loaded CdS powder from aqueous solutions of sodium sulfite is enhanced by addition of a small amount of ethylenediaminetetraacetic acid (EDTA) to the solution EDTA is hardly consumed by the reaction It has been concluded from the measurements of the flat-band potential of CdS electrodes that EDTA and other chelating agents, such as 1,2-cyclohexanediaminetetraacetic acid and nitrilotriacetic acid, are adsorbed strongly on the surface of CdS and shift the conduction band energy toward the negative The enhancement of the photocatalytic hydrogen evolution by the addition of EDTA is explained as being caused by the upward shift of the conduction band energy of CdS due to the negative charge of the chelating agents The change of the conduction band energy by the adsorption of EDTA is observed also for CdSe electrodes Although Pt-loaded CdSe powder is inactive for the hydrogen evolution from aqueous solutions of sodium sulfite, it generates hydrogen when EDTA is added to the solution

Continuous glycerol production by the sulphite process with immobilized cells of Saccharomyces cerevisiae.

Abstract: Glycerol fermentations by the sulphite process with immobilized yeast cells were carried out successfully in continuous culture in a fixed-bed column reactor. In comparison to continuous glycerol fermentations with free yeast cells, fourfold higher dilution rates were obtained. The stability of the immobilized cell system was dependent on dilution rate (D) and temperature. Glycerol yields were influenced by the ratio of sugar to Na2SO3 in the feed. At a flow rate of D = 0.06 h −1 glycerol concentrations up to 25 g1 −1 were measured in the effluent with an average volumetric productivity of 35 g 1 −1 per day. A constant production rate was maintained for nearly 9 months.

Elution process for gold-iodine complex from ion-exchange resins

Abstract: A process for eluting gold-iodine complex from an ion-exchange resin, characterized by adding sulfuric acid and sodium nitrite to the gold-iodine complex adsorbed on the resin, and adding sodium sulfite as an eluant. The process is particularly useful for eluting gold-iodine complex adsorbed on strongly basic anion-exchange resin, such as washings resulting from the washing of leach residue which has been passed through the resin.

The Regulation of Sulfur Use by Ferrous Ion in Thiobacillus ferrooxidans

Abstract: The use of elemental sulfur (S°) as an energy source by T. ferrooxidans API9-3 was completely inhibited by above 108mm of Fe2+ added to S° (l%)-salts medium, in which about 0.6 mm Fe2+ remained after 30 days cultivation without being oxidized. In contrast, the use of Fe2+ by this strain was not inhibited by S°. It was found that specific activities of hydrogen sulfide: ferric ion oxidoreductase (SFORase) and sulfite : ferric ion oxidoreductase, which are crucial in sulfur and sulfite oxidations of this strain, were completely inhibited by 20 mm and 1 mm Fe2 +, suggesting that this may be a main cause for the cells not using sulfur as an energy source. The SFORase activity of the cells incubated with S°-Fe2+-salts medium decreased to 39% of that in control cells without Fe2+, suggesting that Fe2+ added to the medium inhibits a sulfite : ferric ion oxidoreductase, and as a results sulfite ions are accumulated in the cells and this damages the SFORase. Sodium sulfite completely inhibited cell growth on S°-sa...

Sulfinic Acids and Related Compounds 23. Preparation of Sulfinic Acids by the Reaction of Sulfonyl Halides with Thiols

Abstract: The reaction of arene- and alkanesulfonyl halides with p-thiocresol in the presence of triethylamine at −76°C gives triethylammonium sulfinates, which after acidification afford sulfinic acids of 95-100% purity in yields of 51-92% for 18 typical representatives. The synthesis succeeds in certain instances where conventional reduction with aqueous sodium sulfite fails and in other instances often is superior. The method is rapid, mild, selective, convenient, and general, although a few limitations are reported. Characterizations of the sulfinic acids are effected by titration with aqueous sodium nitrite, by IR and 1 H-NMR spectra, by preparation of either a S-benzylthiuronium salt or a p-nitrobenzyl ester, and either by elemental analyses or comparison with reported melting points of the acids and derivatives as appropriate

Chemimechanical pulping of birch wood chips Part 4. Effects of combined sodium hydroxide and sodium sulfite additions

Abstract: Birch wood chips were impregnated with different combinations of sodium hydroxide and sodium sulfite prior to refining, and the effects of the pretreatment on energy requirement, pulp properties and bleachability were investigated. The energy requirement was found to be decreased and the energy utilization enhanced with increased sodium hydroxide addition. Compared at constant freeness level, addition of sodium sulfite was found to increase the refining energy requirement at high addition together with low sodium hydroxide addition. This negative effect of sulfite was not recorded at higher sodium hydroxide additions. The pulp strength properties were also enhanced by increased sodium hydroxide addition, but brightness and light scattering ability were decreased. Sodium sulfite addition increased the brightness and also gave a slight improvement in strength. However, this was accompanied by a simultaneous increase in density. The bleachability of different pulps was excellent, yielding a 36-unit brightness increase at 4% hydrogen peroxide addition and an initial brightness of 33% ISO. The highest brightness obtained was 79% ISO, recorded for a pulp prepared from chips impregnated with 2.3 wt.-% sodium hydroxide and 3.5 wt.-% sodium sulfite on wood resulting in an initial brightness of 58% ISO.

Production of p-toluenesulfonylacetic acid

Abstract: PURPOSE:To obtain the subject compound in high yield by preparing an aqueous solution of sodium p-toluenesulfinate as an intermediate from inexpensive p- toluenesulfonyl chloride as a starting raw material and adjusting pH with a base and/or adding an iodide during reaction with chloroacetic acid CONSTITUTION:For example, sodium sulfite and a base are dissolved or suspended in water and reacted with sodium p-toluenesulfonyl chloride to give an aqueous solution of sodium p-toluenesulfinate as an intermediate raw material In reacting the aqueous solution with chloroacetic acid, the reaction solution is adjusted to pH10-40 with a base such as sodium hydroxide and/or an iodide such as lithium iodide or sodium iodide (preferably about 002-006mol based on 10mol sodium p-toluenesulfinate) to give p-toluenesulfonylacetic acid in high yield p-Toluenesulfonylacetic acid is useful as an intermediate raw material for diiodomethyl-p-tolylsulfone suitable as industrial germicide and fungicide

Production for N,N'-dimethyl-3,3'-dithiodipropionamid

Abstract: The present invention refers to a method for producing N,N'-dimethyl-3,3'-dithiodipropionamide, which is the synthetic intermediate of anti-corrosive 2-methyl-4-isothiazoline-3-one and 5-chloro-2-methyl-4-isothiazoline-3-one. It is obtained by direct reaction of an intermediate, 3,3'-dithiomethyldi propanate, with aqueous solution of methyl amine. The said intemediate, 3,3'-dithiomethyldipropanate, is obtained by reaction of methyl acrylate with sodium polysulphide in ammonium sulphide solution and hydrochloric acid and then treated with aqueous solution of sodium sulfite. The present method is simple in process technology, high in yield, easy to operate and free from environmental pollution.

Mechanism of the inhibition of phloem loading by sodium sulfite: Effect of the pollutant on the transmembrane potential difference

Abstract: Sodium sulfite (Na2SO3) decreased uptake from 1 mM sucrose by the parenchyma and by the veins of leaves of broadbean (Vicia faba L. cv. Aguadulce). The decrease depended on the concentration of the pollutant and the duration of pretreatment. The inhibition was non-competitive. Sulfite affected the transmembrane potential difference (PD) of the leaf tissues. The short-term response obeyed an ‘all or nothing’ law. At 0.1 mM and above, sulfite led to a quick depolarization of one-third of the initial potential after a lag phase of about 5 min; for concentrations lower than 0.1 mM, sulfite did not affect the potential. By contrast, the long-term effect of Na2SO3 on the transmembrane PD strongly depended on its concentration. After 2–12 h of pretreatmemt there was no effect at 10 μM, a weak effect at 0.1 mM, and then increasing depolarization as the pollutant concentration increased. The inhibitory effect of Na2SO3 on sucrose uptake is thus, at least partly, due to its effect on a component of the proton-motive force. ΔΨ. However, the lack of correlation noticed with 0.1 mM Na2SO3 between the effect on sucrose uptake and the long-term effect on transmembrane PD suggests numerous sites of sulfite action.

Anaerobic bacteria immobilizing gel and production thereof

Abstract: PURPOSE: To stably fix anaerobic bacteria while maintaining activity by removing the dissolved oxygen in a gel base material or lowering an oxidation reduction potential. CONSTITUTION: Reducing agents, such as sodium thioglycolate, potassium thioglycolate, cysteine-hydrochloate, sodium sulfide, potassium sulfide, ascorbic acid, sodium sulfite, and sodium hydrogensilfite are charged into the gel base material to stably fix the anaerobic bacteria while holding the same or the reducing agents are charged into a solidifying liquid or washing liquid when the solidifying liquid is required for gelatinization or when washing is required. The dissolved oxygen is decreased to ≤0.1ppm or the oxidation reduction potential is lowered to ≤0mV by charging of the reducing agents in such a manner. Further, the atmosphere is substd. with nitrogen, helium, argon, carbon dioxide, etc., under the perfect anaerobic condition. The utilization to a methane fermentation treatment, etc., is possible and the industrial value is extremely high. COPYRIGHT: (C)1991,JPO&Japio

Epoxidation treatment of animal fiber material

Abstract: PURPOSE: To provide an animal fiber material with shrink resistance without impairing essential characteristics of the fiber by subjecting the animal fiber material to a wetting-deswelling treatment with a saturated aqueous solution containing a neutral salt, then adding a reducing agent to the solution, carrying out a reduction treatment and performing cross-linking and polymerization by a treating solution containing an epoxy compound. CONSTITUTION: An animal fiber material is subjected to a wetting-deswelling treatment with a saturated aqueous solution containing preferably sodium chloride at 30-50 deg.C and then a reducing agent (e.g. acidic sodium sulfite) is added to the solution. The animal fiber material is reduced with the solution at 30-50 deg.C and 1-5% wt/v of an epoxy compound (preferable example glycerol glycidyl ether) and an acidic sulfite as a catalyst are added to the solution to give a treating solution. The animal fiber is treated with the treating solution to perform a cross-linking treatment between scales. An elevation of scales in water controlled to prevent felt formation of the fiber. Neither damage of water repellence of skin being essential characteristics of the fiber nor reduction in mechanical strength of the fiber are brought about by the treatment.

Production of polyacrylic acid metallic salt

Abstract: PURPOSE:To obtain a polymer having improved water absorbing properties and gel strength and useful for paper diaper and a raw material for sanitary good by suspending an aqueous solution of acrylic acid metallic salt containing a water soluble radical generating agent, etc., and having a specific concentration into an aliphatic hydrocarbon solvent and polymerizing the acrylic acid metallic salt. CONSTITUTION:30-40wt.% aqueous solution of acrylic acid metallic salt containing a water-soluble radical generating agent (e.g. potassium persulfate) or redox type polymerization initiator (e.g. combination of potassium persulfate and sodium sulfite) is suspended into an aliphatic hydrocarbon solvent (e.g. pentane) and the acrylic acid metallic salt is polymerized in the presence of a crosslinking agent [e.g. N,N'-methylenebis(meth)acrylamide] to provide the aimed polymer.

Oxidised sulfur dye dispersions purified by membrane separation

Abstract: An aqueous sulfur dye dispersion, which has been oxidised (aerated) to remove inorganic sulfides, is subjected to separation by a semipermeable membrane in order to remove inorganic salts. … The dispersion may also be pre-treated with - … … (i) sodium sulfite or sodium nitrite, to reduce the polysulfur content; … (ii) a surfactant, to prevent agglomeration of the dye particles. … … The resultant odourless suspensions preferably have a dye particle size of

Production of (4-(phenylsulfonyl)phenylsulfonyl)acetic acid and related compound

Abstract: PURPOSE:To enable advantageous production of the title compound used as a thermally developing sensitive material, without the process for waste disposal by sulfonation, chlorination and reduction of a readily available and inexpensive diphenyl sulfide as a starting substance, followed by condensation reaction of the intermediate product with chloracetic acid and oxidation. CONSTITUTION:Diphenyl sulfide of formula I is used as a starting substance to effect sulfonation preferably with chlorosulfuric acid at -10-+50 deg.C to give 4-(phenylthio)benzenesulfonic acid of formula II. The product is chlorinated, preferably with thionyl chloride to give 4 (phenylthio)benzenesulfonyl chloride of formula III. The product is reduced, preferably with sodium sulfite to give the compound of formula IV, which is condensed with chloracetic acid, bromacetic acid or their ester, and the product of formula V (R is H, methyl, ethyl) is oxidized or oxidized, then hydrolyzed to give the compound of formula VI.

Sulfosuccinic acid monoester

Abstract: NEW MATERIAL:The compound of formula I (R1 is 6-12C alkyl; R2 is 4-10C alkyl; AO is 2-4C oxyalkylene; n is 0-20; M1 and M2 are H, alkali metal, ammonium or alkanolamine). USE:Body-cleaning agent. The frothing property can be remarkably improved by using the compound as a shampoo base in combination with a phosphate-type surfactant. PREPARATION:The compound of formula I can be produced e.g., by reacting beta-branched alcohol and its ehtoxylate in the presence of a catalyst such as maleic acid anhydride or sodium acetate at about 80-90 deg.C, adding water and sodium sulfite to the reaction mixture and reacting at 70-80 deg.C for 2-3hr. A shampoo composition is prepared by compounding 5-100 pts.wt. (preferably 10-60 pts.wt.) of the compound of formula I to 100 pts.wt. of a phosphate-type surfactant of formula II [R3 is 10-16C alkyl; m is 0-10; E is OM3 (M3 is H, alkali metal, etc.), etc.].

Stabilization of color of antibacterial preparation

Abstract: PURPOSE: To obtain an aqueous antimicrobial medicament capable of suppressing unnecessary coloring effect, useful as a scurf-preventing agent in a hair- treatment medicament by allowing 1-hydroxy-2-pyridones to include a water-soluble salt generating sulfite ion. CONSTITUTION: This aqueous antimicrobial medicament contains pa water-soluble salt generating sulfate ion (e.g. sodium sulfite, potassium sulfite, lithium sulfite) of 0.05-10wt.%, especially 0.05-2wt.% concentration added to 1-hydroxy-2- pyridones such as the formula (R is H, a 1-17C alkyl, etc.; R is H a 1-4C alkyl, etc.; R is H, a 1-4C alkyl, etc.; R is H, a 1-4C alkyl, a 2-4C alkenyl, etc.). The most preferable compound of the formula is an ethanolamine salt of 1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)-2(1H)-pyridone.

Electroless gold plating solution

Abstract: PURPOSE: To form a thick gold plating excellent in patterning property and appearance by using an electroless-plating soln. contg. a water-soluble gold sulfite compd., a water-soluble polyamino-polycarboxylic acid, a water-soluble amine, a thiosulfite, a sulfite and a hydrazine compd. CONSTITUTION: An electroless gold plating soln. contg. about 1-8g/l of a water- soluble gold sulfite compd. (gold sodium sulfite, etc.,) as the gold ion, about 10-150g/l of a water-soluble polyamino-polycarboxylic acid (ethylenediaminetetraacetic acid, etc.,) or its salt, about 1-10g/l of a water soluble amine (triethanolamine, etc.,) or its derivative, about 1-50g/l of a thiosulfite (ammonium thiosulfite, etc.,) and about 5-50g/l of a hydrazine compd. (hydrazine hydrochloride, etc.,) is prepared, and plating is carried out at about pH 5.0-10.0 and at the soln. temp. of about 30-95°C. Consequently, a thick gold plating excellent in patterning property and appearance is safely applied on a fine circuit board without dissolving the resist. COPYRIGHT: (C)1991,JPO&Japio

Bleaching of ink-discharged pulp

Abstract: PURPOSE: To provide a method for bleaching deinked pulp, capable of bleaching to high levels of whiteness by conjointly treating the deinked pulp with a sulfite and a reducing agent more electronegative than the sulfite ion in a medium having a specific pH value CONSTITUTION: This method for bleaching deinked pulp comprises conjointly treating the deinked pulp with a sulfite bleaching agent, eg sodium sulfite, sodium bisulfite, a mixture thereof, or sulfur dioxide and sodium hydroxide, and a reducing agent more electronegative than the sulfite ion, (preferably thiourea dioxide, sodium borohydride or sodium dithionite), in a reaction medium having an initial pH value ranging from 6 to 12, preferably 7, (preferably at a temperature of 65-95 degC), washing off the sulfite and the reducing agent from the bleached pulp, and then treating the washed pulp with hydrogen peroxide preferably in an aqueous alkaline medium The sulfite, the thiourea dioxide and the sodium borohydride are preferably used in amounts of 01-10 wt% (converted into sulfur dioxide), 01-5 wt% and 001-05 wt% respectively, based on the dry weight of the deinked pulp

Preparation of 4-halogenothiophenol

Abstract: PURPOSE:To profitably prepare a 4-halogenothophenol useful as an intermediate for agricultural chemicals, drugs or dyes in a high yield and a purity by reducing a 4-halogenobenzene sulfinic acid with zinc in the presence of a mineral acid. CONSTITUTION:A 4-halogenobenzene sulfinic acid is reduced with zinc preferably in an amount of the theoretical amount to 1.2 times moles in the presence of a mineral acid, especially sulfuric acid, at 50-90 deg.C, preferably 70-80 deg.C, to inexpensively profitably prepare a 4-halogenothiophenol, especially 4- chlorothiophenol, at an ordinary temperature and a low temperature in simple operations using the zinc and mineral acid reduced to the half amounts and in a yield of >=90% and a purity near 100%, which have never been achieved. When used as a starting substance, 4-halogenobenzene sulfonyl chloride may be reduced with sulfurous acid or alkali metal salt thereof such as sodium sulfite to provide the above-mentioned raw material.

Avoiding total reduced sulfur (TRS) emissions from sodium sulfite pulping recovery processes

Abstract: This paper reports that one of the current trends in paper-making with cellulose pulping is the use of high-yield processes. With yields greater than 65%, these processes include mechanical pulps (groundwood and thermomechanical pulps or TMP), and semichemical types (chemi-TMP or CTMP). Groundwood and TMP make up about 10% of North American pulp production. Semichemical pulp makes up about 7% and is mostly used for corrugating medium. High-yield pulping for linerboard, particularly using the alkaline sulfite process, is also likely to be used in the future. High-yield pulping is based primarily on the sulfite process using mostly sodium-based chemicals. A disadvantage of this process is the unavailability of a recovery system for the inorganic pulping chemicals. Generally, mills have not accepted any particular recovery system for this process. For this and other reasons, sulfite processes constitute only 3-4% of the total North American pulp production. If high-yield processes continue to increase in popularity, a sodium sulfite chemical recovery system will be needed. A number of chemical recovery systems have been developed in the past 30 years for sodium-based sulfite pulping processes, with most of the mills successfully using this process located in Scandinavia.

Film peeling method for magnetic recording medium

Abstract: PURPOSE:To shorten the processing time and to enable film peeling even in an aqueous solution of hydrochloric acid at low concentration by treating a magnetic recording medium in a solution of hydrochloric acid with a reducing agent added. CONSTITUTION:Magnetic recording medium is treated in an aqueous solution of >=4wt.% hydrochloric acid with a reducing agent added. If the concentration of the solution is <4wt.%, the treating time becomes too long for industrial use. The reducing agent added into the solution is selected from hydrazine and sulfur compd. such as sodium hydrogen sulfite, sodium thiosulfate, sodium sulfite, sulfurous acid, etc. One of these or a mixture of two or more compds. are used. By this method, the Cr base layer and the magnetic thin film layer of the medium rapidly dissolve in the hydrochloric acid solution without causing peeling of the Ni-P plating layer. Thus, the Cr base layer, magnetic thin film layer and protective layer formed on the magnetic layer can be removed easily.

Production of sodium sulfite

Abstract: PURPOSE:To reduce contents of Glauber's salt, moisture and fine powder, improve fluidity and prevent solidification by reducing mother liquor concentration after depositing crystal, simultaneously drying deposited and separated Na2SO3 with hot air and directly cooling the dried Na2SO3 in dry air CONSTITUTION:A waste gas containing sulfurous acid gas is brought into contact with a solution containing NaOH and/or Na2SO3 to provide a solution containing acidic Na2SO3 and neutral Na2SO3 in high concentrations The resultant concentrated solution is then led to a crystallizer and NaOH is added to deposit anhydrous Na2SO3 and regulate the mother liquor concentration after depositing the crystals to <=1220g/l The deposited Na2SO3 is subsequently centrifuged, dried with hot air, directly fluidized in dry air below ambient temperature and cooled to <=30 degC

New Pentafluorothio(SF5) Alkylsulfonic Acids.

Abstract: New pentafluorothioalkylsulfonic acids, F5SCXHCY2SO3H (X, Y = H, F), and the corresponding salts have been prepared from pentafluorothioalkyl bromides or olefins with sodium sulfite or sodium bisul...

Reaction of 4-methyl-3,4-epoxytetrahydropyran with nucleophiles

Abstract: Reaction of 4-methyl-3,4-epoxytetrahydropyran with phenols, thiols, thiocyanic acid and benzoic acid, thiourea, and with sodium sulfite and thiosulfate occurs with opening of the epoxide ring. Using IR spectroscopy it was shown that the products occur via trans-diaxial opening of the oxide ring at the least-substituted carbon atom.