Aqueous Sodium Bisulfite Research Articles

Characterization of Sulfited Fat From Limed Hides Fleshing as a Leather Fatliquor

The limed fleshing is generated in the beam house process, is the largest amount of waste, rots easily and causes a pungent smell that pollutes the environment. The use of limed fleshing in fatliquor is an effort to suppress the occurrence of pollution. The purpose of this study is to determine the physico-chemical properties of fatliquor from limed fleshing. Delimed fleshing with ammonium sulfate and water on a rotating drum. Fat was extracted from delimed fleshing using the wet rendering method and purified using n-hexane. The fat from delimed fleshing was characterized and then processed into a fatliquor. The fatliquors is prepared by reacting fat with aqueous sodium bisulfite (0.5, 1.0, 1.5, 2.0, and 2.5 mol/kg based on fatty matters) at a temperature of 85° C for 2 hours. The results showed that fat from limed fleshing can be used to produce fatliquors substances. Based on the physico-chemical properties, the best fatliquors agent is prepared by treating sodium bisulfite with 2.0 mol/kg based on fatty matters.

Modification of urea-formaldehyde resin adhesives with blocked isocyanates using sodium bisulfite

Polymeric 4-4 diphenyl methane diisocyanate (pMDI) was blocked with an aqueous sodium bisulfite solution to obtain water-dispersible blocked pMDI (B-pMDI) resin with different HSO3/–NCO mole ratios for the modification of urea-formaldehyde (UF) resin. Fourier transform infrared (FTIR) spectra of the B-pMDI resin clearly showed that all isocyanate groups of the pMDI resin were successfully blocked by sodium bisulfite. As the HSO3/–NCO mole ratio increased, the de-blocking temperature of the B-pMDI resin also increased. Two addition levels (1% and 3%) of the B-pMDI resin with different HSO3/–NCO mole ratios were mixed with UF resins and used as an adhesive for plywood. The gel time of the UF/B-pMDI resins decreased to a minimum at a mole ratio of 0.9 and then increased with the HSO3/–NCO mole ratio, and was consistent with the peak temperature (Tp). However, as the HSO3/–NCO mole ratio increased, the viscosity of the modified UF resins by 1% B-pMDI resin addition slightly increased, whereas those of modified resins with 3% B-pMDI resin addition rapidly increased. The adhesion strengths of plywood bonded with the hybrid resins were greater for 1% B-pMDI resin addition than for 3% B-pMDI resin addition. Formaldehyde emission of plywood bonded with the UF/B-pMDI resins significantly decreased up to 34% by the addition of B-pMDI resin at a mole ratio of 1.8. These results suggest that the modification of UF resins by mixing with water-dispersible B-pMDI resin can be a method for improving the water resistance and formaldehyde emission of UF resins for wood-based composites.

An efficient and practical procedure for Strecker reaction: a highly diastereoselective synthesis of a key intermediate for (+)-biotin

Treatment of α-amino aldehyde 2 , which was prepared through Moffatt oxidation of the corresponding β-amino alcohol 5 , with aqueous sodium bisulfite allowed clean conversion to a water-soluble bisulfite adduct 6 [>99% conversion, 89% yield (two steps)]. The aqueous solution of 6 was treated with benzylamine followed by easy-handling NaCN to effect the Strecker reaction to afford α-amino nitrile 3 with high diastereoselectivity and in high yield ( syn/ anti = 11:1, 95% assay yield). Both the compounds syn- 3 and anti- 3 were converted to a key intermediate 4 for (+)-biotin through S, N-carbonyl migration in high yields.

A novel and short synthesis of (1,4/2)-cyclohex-5-ene-triol and its conversion to (±)- proto-quercitol

(1,4/2)-Cyclohex-5-ene-triol was synthesized starting from cyclohexa-1,4-diene with two different approaches. Photooxygenation of cyclohexa-1,4-diene and epoxy-cyclohexene afforded anti-2,3-dioxabicyclo[2.2.2]oct-7-en-5-yl hydroperoxide and anti-7-oxabicyclo[4.1.0]hept-4-en-3-yl hydroperoxide, respectively. Hydroperoxy endoperoxide was reduced with aqueous sodium bisulfite; hydroperoxy-epoxide with dimethylsulfide-titanium tetraisopropoxide to give 7-oxabicyclo[4.1.0]hept-4-en-3-ol. Acidic hydrolysis of the epoxy-alcohol gave the (1,4/2)-cyclohex-3-ene-triol. Oxidation of the double bond with KMnO 4 resulted in the formation of (±)- proto-quercitol.

Utilization of Highly Deoxynivalenol-Contaminated Wheat Via Extrusion Processing

Deoxynivalenol (DON) is a toxic natural metabolite produced by Fusarium graminearum. In this study we investigated the effects of sodium bisulfite and extrusion cooking under high temperature and pressure on DON levels in wheat grain and mill fractions. Samples of highly naturally DON-contaminated soft winter wheat were soaked for 1 h in water or aqueous sodium bisulfite (SB) solutions (0.5, 1.5, 2.5, or 5% SO2 equivalent) and extruded. The soaking treatment with SB solution (5% SO2 equivalent) lowered DON from 7.3 μg/g to 0.8 μg/g without extrusion and to 0.3 μg/g with an extrusion process. When the contaminated kernels were tempered with water or SB solutions (5 or 10% SO2 equivalent) and milled, the flour samples, as expected, showed lower levels of DON (from 7.3 to 3.1 μg/g). Extrusion of milled flour and whole meal samples, both obtained from SB-tempered wheat, did not change DON levels significantly under the studied extrusion conditions as compared to the nonextruded milled flour and whole meal samples. However, the extrusion process can be utilized to remove moisture and/or odor of chemicals used in the soaking solutions and to produce potentially useful extruded products.

Detection and Estimation of Part-per-Billion Levels of Formaldehyde Using a Portable High-Throughput Liquid Absorption Air Sampler

In view of the known adverse health effects of formaldehyde and its suspected carcinogenicity, a convenient and simple apparatus for its rapid detection is highly desirable. A portable high-throughput liquid absorption air sampler (PHTLAAS) was therefore evaluated for the rapid and ultrasensitive detection of formaldehyde. Controlled concentrations of formaldehyde in air were generated with a constant-drive syringe pump and mixing chamber apparatus and were either sampled by the PHTLAAS, at a rate of about 200 L/min, or fed to two series-connected liquid impingers. In either case, the formaldehyde was absorbed in a small volume of aqueous sodium bisulfite and measured by the chromotropic acid method. The reddish-purple color of the chromogen formed with chromotropic acid provides a sensitive test for the screening of low levels of formaldehyde in ambient air. Comparison of samples collected from the test sampler with those from the impingers before and after each test yielded PHTLAAS collection efficienci...

Analysis of Aldehydes and Ketones in the Headspace of Heated Pork Fat

ABSTRACTVolatile chemicals in the headspace above heated pork fat were purged into aqueous solutions of cysteamine, sodium bisulfite, or methylhydrazine to trap aldehydes and ketones. Nine aldehydes and four ketones were determined as thiazolidine derivatives in traps containing aqueous cysteamine or aqueous sodium bisulfite. The major compounds produced were hexanal, heptanal, and pentanal. In general, aqueous cysteamine was more efficient at trapping carbonyl compounds than was aqueous sodium bisulfite. However, formalydehyde and acetaldehyde were trapped better by sodium bisulfite solution than by cysteamine solution. Acrolein and malonaldehyde were determined as l‐methyl‐2‐pyrazoline and 1‐methylpyrazole, respectively, from the trap containing methylhydrazine. This represents the first time that malonaldehyde has been determined in the vapor phase.

Monitoring of formaldehyde in air.

Any one of several monitoring methods, depending on requirement and circumstance, can be used to measure employee exposure to formaldehyde. Ordinarily, monitoring at DuPont is performed by sampling with impingers containing 1% aqueous sodium bisulfite or with silica gel tubes. The collected formaldehyde is measured spectrophotometrically after reaction with chromotropic acid. Results from studies on a selected number of formaldehyde monitoring methods reveal that reliable methods are available for area and personnel monitoring over both short term and long term. Accurate results are obtained from short-term monitoring (15 min at 1 L/min) with impingers of formaldehyde concentrations as low as 0.14 ppm. The current studies show that long-term monitoring (8 hr at 0.5 L/min) can be performed accurately at concentrations as low as 0.05 ppm. Accurate results also are obtained from short-term monitoring (15 min at 500 mL/min) with silica gel tubes of concentrations as low as 0.11 ppm formaldehyde; the lower limit established in the current studies for long-term monitoring (8 hr at 30 mL/min) is 0.15 ppm. Passive monitors provide the most convenient means of obtaining 8-hour time-weighted average (TWA) data. The Pro-Tek Formaldehyde Badge was demonstrated to reliably monitor formaldehyde concentrations varying from 0-0.5 ppm or 0-3 ppm. All of these methods satisfy the NIOSH criterion for acceptability that all results fall within +/- 25% of the true value at the 95% confidence level. Investigation of the Lion Formaldemeter disclosed that instantaneous and accurate (+/- 5%) measurement of formaldehyde in air can be made over a concentration range of 0.3-5 ppm in the absence of other substances that are oxidizable in its fuel cell detector.

The effect of disinfectants and heat on hepatitis B virus

Pooled human plasma (JHB 001) was employed as the inoculum, which was positive for HBsAg, HBeAg and DNA polymerase. The logi titre of HB virus was known to contain lo8 chimpanzee infectious doses per millilitre (Shikata et al., 1977). The virus was exposed to 1 and 0.1 w/v per cent aqueous glutaraldehyde (‘Sterihyde’, Maruishi) treatment at 24°C for 5 min and 80 per cent aqueous ethan.01 (Katayama) at 11°C for 2 min. Duplicate lml (glutaraldehyde) or 0.2 ml (ethanol) portions of plasma were treated to give the final concentration as mentioned above. Glutaraldehyde was neutralized by aqueous sodium bisulfite and ethanol was neutralized by dilution in 200 ml of saline solution. To determine the susceptibility of HB virus to heat, duplicate l-ml ampoules containing the contaminated plasma were heated in a bath of liquid paraffin at 98°C for 2 min; the ampoules were placed in the paraffin bath for 6 min as it took 4 min to reach 98°C in preliminary studies. After heating, the ampoules were cooled immediately in an ice-water bath. Plasma dilutions at treatment were 1:2000 for 1 per cent glutaraldehyde, 1 :lOOO for 0.1 per cent glutaraldehyde, 1 :1500 for 80 per cent ethanol or 1: 1000 for heating at 98°C.

Gas absorption with instantaneous chemical reaction. Absorption of sulfur dioxide by aqueous sodium bisulfite

Equations permettant d'estimer la vitesse d'absorption d'un gaz avec diffusion ternaire dans l'absorbant

Studies on cellulose cigarette smoke. IV. Carbonyl compound composition of cellulose cigarette smoke condensate.

In the course of systematic studies of cellulose cigarette smoke, carbonyl compounds extracted with aqueous sodium bisulfite solution were examined and 63 compounds-15 furans, 13 cyclic ketones, 8 lactones, 7 benzene derivatives, and 20 aliphatic ketones, aldehydes and other compounds-were either positively or tentatively identified. Of these 63 compounds, 45 were identified for the first time in this study in cellulose pyrolyzate. Semi-quantitative estimation of some of these compounds revealed that 2-hydroxy-3-methyl-2-cyclopenten-1-one (cyclotene) was the most abundant, followed by 1-hydroxy-2-propanone (acetol), 2-furaldehyde, 1-hydroxy-2-butanone, cyclopentan-l, 2-dione, etc., in decreasing order. Compo-unds possessing pleasant caramel-like odor were found to be relatively abundant both in number and quantity.

Poly(carbamoyl sulfonates) (bisulfite adducts of polyisocyanates)

In the reaction with aqueous sodium bisulfite of polyisocyanates derived from a poly(propylene oxide triol) (molecular weight 3000) and various diisocyanates, bisulfite adducts or poly(carbamoyl sulfonates) (PCS) are not formed unless a water-miscible lower alcohol or ether is used as solvent; and, with aromatic isocyanates, unless additional sulfite and/or a tertiary amine is added. The influence of reaction conditions on the yield of PCS has been examined in detail for the polyisocyanates derived from hexamethylene diisocyanate and 2,4-tolylene diisocyanate. PCS are water soluble, stable in acid solution, and hydrolyze in alkaline solution or on heating to insoluble polyureas. The chemistry of the reactions of PCS is reviewed and potential applications discussed.

Absorption of sulfur dioxide into aqueous sodium hydroxide and sodium sulfite solutions

AbstractThe rates of absorption of pure sulfur dioxide into aqueous sodium bisulfite, sodium hydroxide, and sodium sulfite solutions with and without a surface active agent were measured at 25°C using a liquid jet column. For the sulfur dioxide‐sodium hydroxide system, the rate of absorption into the solution without surface active agent was higher than that into the solution with surface active agent, indicating the existence of the interfacial turbulence. The absorption rates obtained for the present system under the conditions of no interfacial turbulence were in good agreement with the theoretical predictions based on the penetration theory.

Reaction of 5-Carboxypyrimidine Derivatives with Sodium Bisulfite

5-Carboxyuracil derivatives were shown to react with aqueous sodium bisulfite in mild condition resulting in facile decarboxylation to give corresponding 5-decarboxy-5,6-dihydrouracil-6-sulfonates and uracils in good yield. The former compounds were quantitatively transformed to the latter in alkaline condition. Mechanistic feature of this reaction was discussed, which implied the initial nucleophilic addition of bisulfite across the 5,6-double bond. 5-Carboxycytosine was also shown to react similarly, however, accompanied by hydrolytic deamination.

CRIMPING OF MERINO WOOL FIBER TREATED WITH CHEMICAL REAGENTS

Merino wool fibers were treated with aqueous sodium bisulfite (a mild breaking agent for cystine cross-inkages) and followed by the treatment with aqueous alkali (an attacker for ortho-cortex in wool structure). The crimp force i.e. load (P mg) to pull out crimps of a single fiber and the number of crimps per unit length (cm) of extended fiber without stretching were measured before and after above treatments. Stress-Strain curves of the treated fibers, as well as increments of their elastic and plastic regions were also obtained.The results are summarized as follows:1) The treatment with sodium bisulfite solution at 20°C for 30 min did not alter the crimp force and the number of crimps, but treatments at 60°C and 80°C for 30 min minimized the crimp force.2) The number of crimps in wool fiber treated with sodium bisulfite followed by alkali treatment increased remarkably and the crimp configuration became much more homogeneous.3) Magnitudes of crimp force per crimp decraesed in the following order (independent of pretreatment); in air > in water > in chemical reagent solutions, and they were inversely proportional to degrees of swelling of fibers in measuring media.4) Percentages of decrease in elasticity in the elastic regions and increase in plasticity in the plastic regions of a fiber seem to be correlated with degrees of swelling of the fibers.

Reduced quinolines and quinolinium compounds—I : Reduction of quinoline analogs of model compounds for coenzyme

The reduction of quinoline analogs of model compounds for coenzyme I was investigated. The reaction of 1-benzyl-3-carbamidoquinolinium chloride (I) with alkaline sodium dithionite yielded predominantly a stable product which was shown to be sodium 1-benzyl-1,4-dihydro-3-carbamido-4-quinoline sulfonate (II). Compound II was also obtained from the reaction of I with alkaline sodium bisulfite. The reaction of II with sodium dithionite yielded 1-benzyl-1,4-dihydro-3-carbamidoquinoline (III). When II was treated with a variety of acids, a new compound (V) was obtained and identified as 1-benzyl-3-carbamidoquinolinium 1-benzyl-1,4-dihydro-3-carbamidoquinoline-4-sulfonate. This compound was also obtained from the reaction of I with aqueous sulfur dioxide or thionyl chloride and pyridine or aqueous sodium bisulfite. 1-Methyl-3-carbamidoquinolinium iodide (VI) was reduced by alkaline sodium dithionite to yield 1-methyl-1,4-dihydro-3-carbamidoquinoline (VII). Compound VII reduced hexachloroacetone to hexachloroisopropanol in 10% yield.