Showing papers on "Sodium sulfite published in 2012"

Silver nanoparticles synthesis in aqueous solutions using sulfite as reducing agent and sodium dodecyl sulfate as stabilizer

Abstract: The synthesis of silver nanoparticles has been carried out in aqueous solutions in a stirred semibatch reactor through the reduction of silver ions (Ag+) by sulfite ions (SO3 2−), which were added at a tightly controlled rate up to a final sulfite/silver molar ratio of 0.45. Sodium dodecyl sulfate (SDS) was used as the stabilizer at concentrations below its critical micelle concentration. The effects of temperature, sulfite addition rate, and SDS concentration have been assessed. Ag+ turned to Ag0 in 5 min or less only when the synthesis was performed at 97 °C and not below. The sulfite addition rates studied were 0.5, 7.5, 15, and 90 μmol/min. The size, shape, polydispersity, and stability of the nanoparticles were determined by the sulfite addition rate and SDS concentration. At low SDS concentration (4 mM), stable, spherical shape, small size nanoparticles were formed only at the two intermediate sulfite addition rates. At the highest sulfite addition rate, 9 nm mean size spherical nanoparticles having a low ±5 nm polydispersity were produced at a high SDS concentration of 10 mM. With the low SDS concentration, larger truncated and spherical shape nanoparticles were obtained. UV–Vis spectrophotometry and transmission electron microscopy were used to characterize the nanoparticles.

New photocatalysts based on cadmium and zinc sulfides for hydrogen evolution from aqueous Na2S-Na2SO3 solutions under irradiation with visible light

Abstract: Noble metal-free, Cd1 − x Zn x S-based photocatalysts for hydrogen evolution from aqueous solutions of sodium sulfide and sodium sulfite upon irradiation with visible light (λ > 420 nm) have been synthesized and characterized by a complex of physicochemical methods. The effects of pH and catalyst and substrate concentrations on the rate of photocatalytic hydrogen evolution have been investigated. Under the optimal conditions, the quantum efficiency of the process is up to 12.9%.

Contact allergy to sodium sulfite and its relationship to sodium metabisulfite.

Abstract: Background. Sulfites are in widespread use as preservatives/antioxidants. There is increasing recognition of allergic contact dermatitis caused by sodium metabisulfite; however, contact allergy to sodium sulfite is less well recognized. Objectives. We sought to establish the prevalence of positive patch test reactions to sodium sulfite in our patient population and investigate its relationship with sodium metabisulfite. Methods. Over a 4-month period, 183 patients referred for patch testing were tested with sodium sulfite 1% pet. in addition to sodium metabisulfite 1% pet., which already forms part of our baseline series. Results. Positive allergic reactions occurred to sodium metabisulfite in 5.5% of the tested patients and to sodium sulfite in 3.8% of the tested patients. Sixty per cent of patients with a positive reaction to sodium metabisulfite were positive to sodium sulfite. Only 1 patient (0.6%) with a negative reaction to sodium metabisulfite showed a positive reaction to sodium sulfite. Conclusions. This study shows that the majority of patients with positive reactions to sodium metabisulfite are also positive to sodium sulphite. Routinely patch testing with sodium sulfite is probably unnecessary, as most patients with positive reactions will also react to sodium metabisulfite. Clinicians should consider advising patients to avoid sodium sulfite and other sulfites when a positive allergic reaction to sodium metabisulfite occurs.

Performance of a pilot-scale packed bed reactor for perchlorate reduction using a sulfur oxidizing bacterial consortium.

Abstract: A novel sulfur-utilizing perchlorate reducing bacterial consortium successfully treated perchlorate (ClO) in prior batch and bench-scale packed bed reactor (PBR) studies. This study examined the scale up of this process for treatment of water from a ClO and RDX contaminated aquifer in Cape Cod Massachusetts. A pilot-scale upflow PBR (∼250-L) was constructed with elemental sulfur and crushed oyster shell packing media. The reactor was inoculated with sulfur oxidizing ClO reducing cultures enriched from a wastewater seed. Sodium sulfite provided a good method of dissolved oxygen removal in batch cultures, but was found to promote the growth of bacteria that carry out sulfur disproportionation and sulfate reduction, which inhibited ClO reduction in the pilot system. After terminating sulfite addition, the PBR successfully removed 96% of the influent ClO in the groundwater at an empty bed contact time (EBCT) of 12 h (effluent ClO of 4.2 µg L−1). Simultaneous ClO and NO reduction was observed in the lower half of the reactor before reactions shifted to sulfur disproportionation and sulfate reduction. Analyses of water quality profiles were supported by molecular analysis, which showed distinct groupings of ClO and NO degrading organisms at the inlet of the PBR, while sulfur disproportionation was the primary biological process occurring in the top potion of the reactor. Biotechnol. Bioeng. 2012; 109:637–646. © 2011 Wiley Periodicals, Inc.

Process for separating and recovering selenium from selenium-containing material

Abstract: The invention relates to a process for separating and recovering selenium from a selenium-containing material. The process comprises the following steps: dissolving the selenium-containing material into a sulfuric acid solution, adding 10% H2O2 into the mixture, filtering and separating to get leachate and residue containing silver, lead, copper and other valuable metals; separating the selenium from tellurium in the oxidation leachate by using sodium hydroxide; and acidifying the selenium leachate with hydrochloric acid, adding sodium sulfite to reduce the settled selenium, washing and drying to get crude selenium with the grade of not lower than 90%. The crude selenium which is separated by the process is higher in purity and can be directly refined, so that the process flow of recovering selenium is shortened, the recovery rate of selenium is improved, the production cost is reduced and the energy is saved; and the sodium sulfite is used for substituting sulfur dioxide to perform reduction, the control is easy and the environmental pollution is further reduced. The process has very important significance in both aspects of recovering resources and protecting an environment.

Water-resistant whey protein based wood adhesive modified by post-treated phenol-formaldehyde oligomers (pfo)

Abstract: With the attempt to develop an environmentally safe whey protein-based adhesive with good water resistance, a low-molecular-weight PFO was used as a modifier, and the effects of scavengers on the formaldehyde emission and bond properties were investigated. Plywood evaluation and HPLC analysis indicated that the PFO synthesized with a low content of sodium hydroxide as a catalyst (NaOH/phenol mole ratio = 0.064) at a low reaction temperature (60-75oC) had good water solubility and very low viscosity that was preferable to the modification of whey protein-based adhesives. Combinations of ammonia and sodium sulfite as formaldehyde scavengers had positive effects on the formaldehyde emissions of plywood panels bonded by the PFO-modified whey protein adhesives and had slight effects on bond properties. A necessary stoichiometric excess of ammonia-sulfite combination during PFO post-treatment is critical to effectively reduce formaldehyde emission. The whey protein-based adhesive modified with the most preferable post-treated PFO is water-resistant and environmentally safe, which had a dry shear bond strength of 1.98 MPa and a 28 hour-boiling-dry-boiling wet shear strength of 1.73 MPa according to standard JIS K6806-2003, a formaldehyde emission of 0.067mg/L according to standard JIS A5908, and undetectable level of free phenol by HPLC.

Concentrated multienzyme cleaning solution and preparation method thereof

Abstract: The invention discloses a concentrated multienzyme cleaning solution and a preparation method thereof, wherein the concentrated multienzyme cleaning solution is prepared from the following raw materials in parts by weight: 1 to 5 parts of organic preservative, 200 to 400 parts of surfactant, 20 to 65 parts of enzyme stabilizer, 40 to 80 parts of propylene glycol, 30 to 80 parts of triethanolamine, 10 to 60 parts of sodium sulfite, 0.1 to 5 parts of calcium chloride, 20 to 60 parts of sodium citrate, 10 to 65 parts of citric acid, 0.1 to 1 part of antifoaming agent, 30 to 80 parts of bio-enzyme, and appropriate deionized water; and the method for preparing the concentrated multienzyme cleaning solution comprises the following steps: dissolving the preservative into the propylene glycol, then adding the surfactant, the triethanolamine and the antifoaming agent into the obtained mixture so as to obtain a solution A; heating the deionized water, and dissolving the enzyme stabilizer, the sodium sulfite, the calcium chloride, the sodium citrate and the citric acid into the deionized water, then cooling the obtained mixture so as to obtain a solution bio-enzyme B; and finally, mixing thesolution A and the solution B so as to obtain the finished product of the concentrated multienzyme cleaning solution. The concentrated multienzyme cleaning solution and the preparation method thereofhave the advantages: the enzyme stabilizer is adopted to effectively protect the activity of the bio-enzyme, and used with the surfactant and the preservative, so that the obtained finished product is stable in performance, long in storage time and strong in capacity of decomposing biological tissues.

Oxidation of Chlorophenols in Aqueous Solution by Excess Potassium Permanganate

Abstract: A simple spectrophotometric method was developed to quantify chlorophenol (CP) concentrations after reaction with potassium permanganate and quenching with sodium sulfite. Other quenching agents (peroxide, sodium thiosulfate and hydroxylamine hydrochloride) were found to create absorbance in the spectral range required for CP quantification. Analysis at pH 12 gave greater absorption and sensitivity for the method compared with pH 5.6. The calibration curves of the proposed methods were linear in the concentration ranges 0.0061–0.61 and 0.0078–0.78 mM with detection limit of 0.0006 and 0.0008 mM for dichlorophenols and monochlorophenols, respectively. The oxidation kinetics of five chlorophenols in aqueous solution with excess potassium permanganate were evaluated using the analytical method. The pseudo-first-order reaction rates were found to be relatively rapid 1.42 × 10−3 to 0.024 s−1 and followed the sequence 2-chlorophenol (2-CP) > 2,6-dichlorophenol (2,6-DCP) > 4-chlorophenol (4-CP) > 2,4-dichlorophenol (2, 4-DCP) > 3-chlorophenol (3-CP). The apparent second-order rate constant was calculated from the measured pseudo-first-order rate constant with respect to CP with initial KMnO4 concentration (1.5 mM) and follows the same sequence of pseudo-first-order rate constant. This shows that chlorine atoms in the structure of chlorophenol had a significant influence on the oxidation of chlorophenols by potassium permanganate. Permanganate can be used for the treatment of chlorophenol-contaminated soil and groundwater.

Method for detecting silicon content in vanadium-aluminum alloy

Abstract: The invention provides a method for detecting the silicon content in a vanadium-aluminum alloy. The method comprises the steps of: establishing a silicon standard solution concentration-absorbance working curve; decomposing a sample to be detected with hydrochloric acid and nitric acid; adding sodium sulfite into the obtained solution to be detected so as to reduce the solution to blue, conducting cooling, and setting the constant volume of the solution in a standard volumetric flask; getting two solutions of certain amount from the standard volumetric flask for detecting, with one solution used as a color developing solution and the other solution used as a reference solution; adjusting the color developing solution to chromogenic acidity, adding excess ammonium molybdate, and disposing the solution for 5-30min so as to generate silicomolybdenum yellow heteropoly acid, then adding a mixed acid of oxalic acid and sulfuric acid, and adding ammonium ferrous sulfate immediately to reduce the silicomolybdenum yellow heteropoly acid generated during reaction to silicomolybdenum blue heteropoly acid, and carrying out dilution to a scale; adjusting the reference solution to chromogenic acidity, adding a mixed acid of oxalic acid and sulfuric acid, ammonium molybdate and ammonium ferrous sulfate, and carrying out dilution to the scale; measuring absorbance at a position of 680nm at a spectrophotometer, looking up the working curve according to the obtained absorbance value of the color developing solution, and calculating the silicon content in the vanadium-aluminum alloy.

Microwave-Assisted Synthesis and Properties of Sodium Glycol Bis-(Isooctyl)Sulfosuccinate

Abstract: An anionic gemini surfactant was synthesized under microwave irradiation conditions. The optimum reaction conditions were obtained by the reaction of maleic anhydride, glycol, isooctyl alcohol and sodium sulfite. The first step esterification reaction was carried out at 90 °C and 100 W microwave power for 20 min with a ratio a n maleic anhydride:n glycol = 2.1:1, and 1.0 wt% of catalyst. The second step esterification reaction was carried out at 80 °C for 25 min and 100 W microwave power. Optimum sulfonation was carried out with n sodium sulfite:n glycol bismaleic anhydride bisester = 2.25:1 and 1.5% catalyst for 25 min at 60 °C. It is found that microwave-assisted synthesis is an efficient means of preparation of this anionic gemini surfactant with shorter reaction times and higher yields. The title compound structure was confirmed by IR. The critical micelle concentration of the title compound is 6.2 × 10−4 mol L−1, γCMC is 25.7 mN m−1, and benzene emulsion persistence was 2 days.

Method for extracting selenium from selenium-contained material

Abstract: The invention relates to a method for extracting selenium from selenium-deposited residue. The method comprises the following steps of: dissolving selenium-deposited residue to an alkaline sodium sulfite solution, generating water-soluble seleno sodium sulfate through a reaction between elemental selenium and the sodium sulfite solution; fully reacting the seleno sodium sulfate under the acidification of sulfuric acid to obtain a selenium elemental precipitate; and washing and drying to obtain coarse selenium with the purity of about 90 percent. The invention realizes separation of copper, silver and selenium in the selenium residue, and the separated selenium can be directly refined due to higher purity, therefore, the process flow of selenium recovery is shortened, the recovery rate is increased, and the production cost is decreased; the trouble of high copper content of an anode plate in silver electrolysis in the gold and silver refining process is solved and the pass rate of primary silver powder electrolysis is increased. The invention can be applied to recovering and extracting selenium from materials, such as selenium-contained residue generated in the technical process byusing a wet method for treatment or selenium-contained acid mud generated in the production process of the copper anode slime by using a pyrogenic method for treatment and can also be applied to the production of high-purity selenium products by directly purifying a coarse selenium raw material.

Novel leveling and dispersing agent

Abstract: The invention discloses a novel leveling and dispersing agent, which consists of the following components in parts by weight: 3-6 parts of fatty alcohol-polyoxyethylene ether, 2-5 parts of sodium dodecylbenzene sulfonate, 5-8 parts of maleic anhydride, 10-20 parts of polyethylene glycol, 2-4 parts of acrylic acid, 4-8 parts of polyacrylamide, 1-3 parts of sodium sulfite and 80-100 parts of water. Compared with the prior art, the novel leveling and dispersing agent has the beneficial effects of superior dyeing retarding, dyeing migrating and dispersing performances, suitability for dying processes under various conditions, and the like.

Animal hair solvent and preparation method and use of keratin solution

Abstract: The invention discloses an animal hair solvent and the preparation method and use of keratin solution. The solvent is characterized in that tris(2-carboxyethyl)phosphine hydrochloride, tris(2-cyanoethyl)phosphine or trisphosphine is used as a main ingredient and is mixed with 1 to 8 percent of assistant which may be at least one of mercaptoacetic acid, mercaptoethanol, sodium hydrogensulfite, potassium bisulfate, sodium sulfite, potassium sulfite, sodium hypophosphite, ethanol, methanol and urea. The preparation method adopts the following processes: 1, preparing animal hair solution by usingthe animal hair solvent of the invention; 2, dissolving animal hair in the solution to prepare keratin solution; and 3, adding a proper amount of acid to perform the post-treatment of the keratin solution. The use is to use the keratin solution as textile finishing liquor or the main functional ingredient of the textile finishing liquor.

Phenol-urea-formaldhyde resin modified lignite filtrate loss reducer with high temperature resistance and salt tolerance, and its preparation method

Abstract: The invention relates to a preparation method of a filtrate loss reducer used for drilling fluids. With lignite as the main material, the method first prepares a sulfonated phenol-urea-formaldhyde resin mixture, which is then reacted with an alkaline solution and lignite, thus obtaining a sulfonated phenol-urea-formaldhyde resin modified lignite filtrate loss reducer. The lignite filtrate loss reducer comprises the following reactants by weight: 10%-20% of lignite; 2%-4% of one of or a mixture of NaOH and KOH; 50%-60% of water; 2%-5.5% of phenol; 8%-15% of formaldehyde; 3%-7% of urea; 0.15%-2% of a hydrolyzed acrylonitrile sodium salt; 0.125%-0.5% of polyacrylamide; and 2%-7% of a sulfonating agent (one of or a mixture of sodium sulfite, sodium bisulfite, and sodium metabisulfite).

Method for determining phosphorus in silicon-manganese alloy

Abstract: The invention discloses a method for determining phosphorus in silicon-manganese alloy, which comprises the steps of: dissolving a test sample by using nitric acid and hydrofluoric acid and adding perchloric acid to convert phosphorus in the test sample into orthophosphoric acid to obtain fist mixed solution; adding sodium sulfite into the first mixed solution to reduce manganese in the silicon-manganese alloy to obtain second mixed solution; and adding bismuth nitrate solution, ammonium molybdate solution, potassium sodium tartrate solution, sodium fluoride and stannous chloride into the second mixed solution, wherein ammonium molybdate can convert the orthophosphoric acid in the first mixed solution into phosphorus-molybdenum heteropoly acid, using stannous chloride to reduce the formed phosphorus-molybdenum heteropoly acid into blue phosphomolybdenum blue and finally using a spectrophotometric method to determine the content of the phosphorus. Compared with the prior art, by using the stannous chloride as the reducing agent, since the stannous chloride has the characteristics of high reducing speed, good reducing effect and the like, the analysis time of the determination method is shorter, the accuracy and the stability of the determination result are improved and the method is suitable for field mass production analysis.

Method for respectively leaching copper and cobalt from copper and cobalt concentrate

Abstract: The invention provides a method for respectively leaching copper and cobalt from a copper and cobalt concentrate. The method comprises the following steps of: (1) ammonia leaching: adding the copper and cobalt concentrate into bottom water, adding ammonium carbonate according to a molar ratio that the ammonium carbonate to the copper element in the copper and cobalt concentrate is 1:4-12, introducing ammonia gas or ammonia water according to the molar ratio that the ammonia gas or the ammonia water to the copper element is 1:4-12, adding sodium chlorate in an amount which is 0.3 to 0.5 times the mass of the copper element, reacting at the temperature of between 30 and 60 DEG C for 1 to 3 hours, and filtering to obtain filtrate and filter residues respectively; and (2) acid leaching: adding the filter residues into the bottom water, adding sulfuric acid or hydrochloric acid to regulate the pH value to be between 0.5 and 1.5, adding sodium sulfite in an amount which is 1.2 to 1.5 times the total mass of the copper element and the cobalt element in the filter residues, reacting at the temperature of between 60 and 80 DEG C for 1 to 3 hours, and filtering to obtain filter residues andfiltrate respectively. In the method, copper can be selectively leached, while the cobalt is not leached in the step of ammonia leaching; and the cobalt and the residual copper can be completely leached in the step of acid leaching.

Paper starch adhesive and preparation method thereof

Abstract: The invention discloses a paper starch adhesive and a preparation method thereof. The paper starch adhesive comprises the following components in part by weight: 100 parts of starch, 300 to 600 parts of water, 0.1 to 0.3 part of potassium hydrogen peroxymonosulfate, 5 to 10 parts of caustic soda, 1 to 5 parts of epoxy chloropropane, 0.5 to 1.5 parts of boric acid, 1 to 3 parts of sodium sulfite, 4 to 8 parts of light calcium carbonate and 2.5 to 5 parts of bridging agent. The preparation method comprises the following steps of: adding water into a reaction kettle, heating the water to 38 DEG C, adding the starch into the water, stirring the solution, adding potassium hydrogen peroxymonosulfate solution into the reaction kettle, and reacting the mixed solution for 20 minutes with stirring;diluting the caustic soda, then slowly adding the caustic soda into the reaction kettle twice, stirring the solution for about 20 minutes to form milk white or light yellow transparent colloid, then adding the boric acid, the bridging agent and the light calcium carbonate into the colloid, and stirring the mixture uniformly; and adding the epoxy chloropropane, sodium aliphatate and the sodium sulfite into the reaction kettle with stirring, and stirring the mixture uniformly to obtain the paper starch adhesive. The adhesive has the characteristics of stable viscosity, good adhesiveness, low comprehensive cost, good permeability and the like.

Method for preparing modified aliphatic water reducing agent

Abstract: The invention discloses a method for preparing a modified aliphatic water reducing agent. The method comprises the following steps of: mixing water, sodium sulfite and acetone in a reactor at 30-35 DEG C for 30 minutes; adding paper making factory waste liquid and a catalyst into the reactor for reacting at 50-60 DEG C for 50-70 minutes; dropwise adding formaldehyde into the reactor for 60-90 minutes; reacting for 2-2.5 hours by controlling the temperature to be 90-105 DEG C; and adding sodium gluconate into the reactor and reacting for 30 minutes by controlling the temperature to be below 90-105 DEG C. The modified aliphatic water reducing agent comprises the following raw materials in parts by weight: 50-55 parts of the sodium sulfite, 35-40 parts of the acetone, 110-125 parts of the formaldehyde, 200-230 parts of the paper making factory waste liquid (lignin content is 30-35 percent by weight), 2-3 parts of boron fluoride etherate, 3-5 parts of the sodium gluconate and 110-130 parts of water. The method has a short preparation time, and the prepared water reducing agent has high water reducing ratio.

High-temperature O2/CO2 corrosion inhibitor for coiled tubing and preparation method of agent B of high-temperature O2/CO2 corrosion inhibitor

Abstract: The invention discloses a high-temperature O2/CO2 corrosion inhibitor for coiled tubing. The high-temperature O2/CO2 corrosion inhibitor for the coiled tubing is used by matching an agent A mainly used for deoxidizing and an agent B mainly used for resisting corrosion of carbon dioxide, wherein the agent A is acetone oxime, D-ascorbic acid, sodium sulfite or ferrous sulphate; and the agent B is formed by mixing the components in percentage by weight: 20-30 percent of quaternary pyridine salt, 10-15 percent of mannich base chelate, 3-7 percent of surfactant and 48-67 percent of solvent. The quaternary pyridine salt is obtained by reacting pyridine with benzyl chloride; and the mannich base chelate is obtained by aldehyde ketone amine condensate generated by morpholine, trioxymethylene and dimethylamine through a mannich reaction with metal chloride. The corrosion inhibitor provided by the invention has use temperature up to 170DEG C, is suitable for a water-corrosive medium in which oxygen and carbon dioxde coexist and can be used for effectively inhibiting the corrosion of media such as the oxygen and the carbon dioxide and ensuring safe operation of the coiled tubing in the production process.

Presença de sulfito de sódio e sua influência nas características físico-químicas e microbiológicas de carnes bovinas moídas resfriadas* Sodium Sulfite Presence and its Influence on Physicochemical and Microbiological Characteristics of Refrigerated Ground Beef

Abstract: Background: Ground meat stands among the most consumed meat products, being its safety easily damaged by increasing the surface area of contact after grinding it, what facilitates the growth of pathogenic and deteriorating micro-organisms. In order to decrease the lost because of deterioration, trade has been utilizing fraudulent devices as the addition of intentional preservative such as sodium sulfite. This research aimed to identify the presence of sodium sulfite in cooled ground beef commercialized in business establishments located in Porto Alegre city, state of Rio Grande do Sul, Brazil. In addition, it addressed the evaluation of the influence of using this addictive in cooled ground meat front its physic-chemical and microbiological characteristics and residual capacity in the first 48 hours. Materials, Methods & Results: A total of 55 samples of cooled ground beef, from non-noble cuts, acquired in business establishments located in Porto Alegre city, were collected. Thus, microbiological analyses for total and thermotolerant coliphorms, Clostridium Sulfite reducers, Staphylococcus coagulase-positive, Salmonella sp. and a qualitative test, for verifying the presence of sodium sulfite, were carried out. Subsequently, half of the negative samples (24) in the sulfite test were separated, and 0.04 g of this addictive for each 50 g of ground beef (0.08%) was, then, added. In these samples, microbiological and color analyses, and the confirmation of the presence of sodium sulfite, at times 0, 24 and 48, after the simulation of fraud of the samples, were realized. Moreover, for the verification of safety, microbiological analyses for Salmonella sp., Staphylococcus coagulase-positive, Clostridium Sulfite reducers, total and thermo tolerant coliphorms were carried out. Data were analyzed by Analysis of Variance (ANOVA), with pairwise comparisons done by the Tukey test, for a level of significance of 5% (P < 0.05). Thereby, from the total of 55 (100%) analyzed samples of cooled ground beef, two (3.63%) showed the presence of sodium sulfite addictive, and the performed microbiological analyses indicated the presence of Salmonella sp. in eight (14.54%) samples. The values of L*, observed in the samples added with sulfite, maintained constant at times (zero, 24 and 48) compared with the control samples (without addition of sulfite) (42.92; 40.35 and 41.69, vs 44.67; 37.65 and 32.38, respectively), which demonstrated lost of luminosity in the course of time. Also, the values of a* and b* demonstrated stable at times (zero, 24 and 48) in the samples added with addictive (5.72; 6.89; 5.47 and 9.73; 10.69; 9.56, respectively), although this has not occurred with the control samples that presented a gradual lost of these tonalities (11.48; 7.21; 5.91 and 16.11; 12.88; 7.84, respectively) (P < 0.05). Discussion: The results indicated that two (3.63%) samples showed the presence of sodium sulfite, being in disagreement with the Ordinance n. 1004 that forbids the addition of addictive a in natura meat. The presence of Salmonella sp. in samples of ground meat contradicts the Resolution RDC n. 12 that advocates its absence in 25 g of meat products. Furthermore, the conducted analyses of color proved that the addition of addictive in meat maintains its fresh color and appearance, beyond inhibiting reactions of enzymatic and non-enzymatic darkness during processing and storage. By considering the obtained results, it may be concluded that despite of a low incidence of fraud for finding sodium sulfite, this practice exists in business establishments located in Porto Alegre city, state of Rio Grande do Sul, Brazil, even though it can be concealed for the lack of continuous studies and legal analytical inspections, endangering sanitary-hygienic conditions of the products.

Presença de sulfito de sódio e sua influência nas características físico-químicas e microbiológicas de carnes bovinas moídas resfriadas

Abstract: Background: Ground meat stands among the most consumed meat products, being its safety easily damaged by increasing the surface area of contact after grinding it, what facilitates the growth of pathogenic and deteriorating micro-organisms. In order to decrease the lost because of deterioration, trade has been utilizing fraudulent devices as the addition of intentional preservative such as sodium sulfite. This research aimed to identify the presence of sodium sulfite in cooled ground beef commercialized in business establishments located in Porto Alegre city, state of Rio Grande do Sul, Brazil. In addition, it addressed the evaluation of the influence of using this addictive in cooled ground meat front its physic-chemical and microbiological characteristics and residual capacity in the first 48 hours. Materials, Methods & Results: A total of 55 samples of cooled ground beef, from non-noble cuts, acquired in business establishments located in Porto Alegre city, were collected. Thus, microbiological analyses for total and thermotolerant coliphorms, Clostridium Sulfite reducers, Staphylococcus coagulase-positive, Salmonella sp. and a qualitative test, for verifying the presence of sodium sulfite, were carried out. Subsequently, half of the negative samples (24) in the sulfite test were separated, and 0.04 g of this addictive for each 50 g of ground beef (0.08%) was, then, added. In these samples, microbiological and color analyses, and the confirmation of the presence of sodium sulfite, at times 0, 24 and 48, after the simulation of fraud of the samples, were realized. Moreover, for the verification of safety, microbiological analyses for Salmonella sp., Staphylococcus coagulase-positive, Clostridium Sulfite reducers, total and thermo tolerant coliphorms were carried out. Data were analyzed by Analysis of Variance (ANOVA), with pairwise comparisons done by the Tukey test, for a level of significance of 5% (P < 0.05). Thereby, from the total of 55 (100%) analyzed samples of cooled ground beef, two (3.63%) showed the presence of sodium sulfite addictive, and the performed microbiological analyses indicated the presence of Salmonella sp. in eight (14.54%) samples. The values of L*, observed in the samples added with sulfite, maintained constant at times (zero, 24 and 48) compared with the control samples (without addition of sulfite) (42.92; 40.35 and 41.69, vs 44.67; 37.65 and 32.38, respectively), which demonstrated lost of luminosity in the course of time. Also, the values of a* and b* demonstrated stable at times (zero, 24 and 48) in the samples added with addictive (5.72; 6.89; 5.47 and 9.73; 10.69; 9.56, respectively), although this has not occurred with the control samples that presented a gradual lost of these tonalities (11.48; 7.21; 5.91 and 16.11; 12.88; 7.84, respectively) (P < 0.05). Discussion: The results indicated that two (3.63%) samples showed the presence of sodium sulfite, being in disagreement with the Ordinance n. 1004 that forbids the addition of addictive a in natura meat. The presence of Salmonella sp. in samples of ground meat contradicts the Resolution RDC n. 12 that advocates its absence in 25 g of meat products. Furthermore, the conducted analyses of color proved that the addition of addictive in meat maintains its fresh color and appearance, beyond inhibiting reactions of enzymatic and non-enzymatic darkness during processing and storage. By considering the obtained results, it may be concluded that despite of a low incidence of fraud for finding sodium sulfite, this practice exists in business establishments located in Porto Alegre city, state of Rio Grande do Sul, Brazil, even though it can be concealed for the lack of continuous studies and legal analytical inspections, endangering sanitary-hygienic conditions of the products.

Method for fast measuring sulphitation Chinese medicinal materials

Abstract: The invention provides a method for fast measuring sulphitation Chinese medicinal materials. The method is characterized by comprising the following steps of: firstly preparing a standard sodium sulfite solution; removing 0-10 ml of the 0.0001-0.001% standard sodium sulfite solution, and placing into a reaction bulb; adding water, and then adding 2-3 grams of zinc granules; adding 5-8 ml of hydrochloric acid solutions, 5-10 ml of brand-new potassium iodide solutions and 5-10 drops of acidic stannous chloride, and immediately plugging an arsenic measuring tube previously loaded with wetting lead acetate test paper; standing at 40-50 DEG C for 1-1.5 hours to obtain lead sulphide spots with different concentrations; taking out the lead acetate test paper; and detecting the sulphurcontent of a sample according to the shade of the colors of the lead sulphide spots. The invention has the advantages of fast detection, low cost, convenience in use and fast measurement of a large amount of residual sulphur, sulphur dioxide and sulphates in various valence states, which are contained in the Chinese medicinal materials; the invention can effectively control the harm of harmful substances contained in the Chinese medicinal materials on human, thereby ensuring the life safety of human; and in addition, the method is convenient for popularization and application.

Electrowinning method for metal manganese

Abstract: PROBLEM TO BE SOLVED: To provide an electrowinning method for metal manganese, by which electrowinning of metal manganese can be performed efficiently, commercially and stablySOLUTION: The electrowinning method for metal manganese includes: an impurity removing step adjusting the pH of a manganese sulfate solution containing nickel and cobalt to 4-7 and then removing nickel and cobalt by sulfurization treatment so that each content of nickel and cobalt becomes 1 ppm by mass or less; an electrolytic solution preparation step adding ammonium sulfate as a pH buffering agent and sodium sulfite, sulfurous acid gas or selenious acid as a reducing agent to the manganese sulfate solution from which nickel and cobalt have been removed, and adjusting the pH of an anolyte and a catholyte with sulfuric acid and manganese carbonate; and an electrolytic step separating an anode and the anolyte by a diaphragm, then supplying the anolyte and the catholyte separately, and performing electrolysis

Preparation method of starch and sulfomethyl phenol graft copolymer leather synthesis tanning agent

Abstract: The invention relates to a preparation method of starch and sulfomethyl phenol graft copolymer leather synthesis tanning agent, the method comprises the following steps: reacting sodium bisulfite with sodium sulfite and formaldehyde, to prepare sodium hydroxymethanesulphonate, then performing a sulfomethylation of hydroxymethyl sulfonate and phenol under the alkaline condition, to prepare a sulfomethyl phenol solution, finally, mixing the sulphur methyland phenol solution with enzymatic degradated starch, regulating the pH value of the solution by sodium bicarbonate, performing a graft copolymerization reaction of starch and sulphur methyland phenol under the catalytic effect of horseradish peroxidase, to obtain the starch graft copolymer leather synthesis tanning agent. The obtained product has the advantages of moderate relative molecular mass, good permeability and high absorption, and is a high-molecular tanning agent with no pollution and green performance. The preparation methodof the present invention has an unique synthesizing preparation technology, the shrinkage temperature can reach at 78 DEG C when the obtained synthesis tanning agent is taken as a main tanning agent,the thickening rate of the leather can reach at 28% when the obtained synthesis tanning agent is used for retanning, thereby the leather possesses soft handfeel. The agent can be used as the leather tanning agent with green environmental protection performance.

Synthesis of Few-Layer Graphene Sheets via Chemical and Thermal Reduction of Graphite Oxide

Abstract: Few-layer graphene sheets were produced from graphite oxide (GO) chemical and thermal reduction. For the chemical reduction of GO as reducing agents were used hydrazine hydrate, hydroxylammonium chloride, sodium borohydride and sodium sulfite. The reduced material was characterized by elemental analysis, thermo-gravimetric analysis, scanning electron microscopy, X-ray diffraction, Fourier transform infrared and Raman spectroscopy. A comparison of the deoxygenation efficiency of graphene oxide suspensions by different method or reductants has been made, revealing that the highest degree of reduction was achieved by thermal reduction and using hydrazine hydrate and hydroxylammonium chloride as a reducing agents.