Topic
Sodium sulfite
About: Sodium sulfite is a research topic. Over the lifetime, 2548 publications have been published within this topic receiving 18523 citations. The topic is also known as: Na2SO3 & Anhydrous sodium sulfite.
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04 Jul 2012
TL;DR: In this article, 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.
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.
8 citations
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TL;DR: In this article, a kinetic method was developed for the determination of 1-naphthylacetic acid by means of micellar-stabilized room temperature phosphorescence (MSRTP) using the stopped-flow mixing technique.
Abstract: A kinetic method has been developed for the determination of 1-naphthylacetic acid by means of micellar-stabilized room temperature phosphorescence (MSRTP) using the stopped-flow mixing technique. The main feature of this system is that it diminishes the time required for the deoxygenation of the micellar medium and for the phosphorescence development. Phosphorescence enhancers such thallium(I) nitrate, sodium dodecyl sulfate (SDS), and sodium sulfite were optimized to obtain maximum sensitivity. The pH was also optimized as it strongly affects the luminescent properties of 1-naphthylacetic acid. A pH of 6.6 was selected as adequate for the phosphorescence development. The kinetic curve of 1-naphthylacetic acid phosphorescence was scanned at lambda(ex) = 278 nm and lambda(em) = 490 nm, and the maximum rate of phosphorescence was taken as the analytical signal. This was obtained by calculating the maximum slope of the curve in an interval of 3.6 s as it provided a good noise-to-signal ratio. This method permitted the determination of 1-naphthylacetic acid throughout a concentration range of 100-1800 ng mL(-1) with high precision (relative standard error = 0.91% and relative standard deviation = 2.30%; 1-naphthylacetic acid concentration = 800 ng mL(-1)). According to the Clayton criterion, the detection limit was 45 ng mL(-1). The same limit resulted in 39.3 ng mL(-1) when the error propagation theory was applied. The applicability of the method was successfully demonstrated by determining 1-naphthylacetic acid in different kind of samples, such as phytosanitary products, soils, pears, and apples. Recovery values not significantly different from the nominal content or the spiked amount were found for these determinations.
8 citations
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TL;DR: In this paper, the thermodynamic probability of dissolution of noble metals in aqueous solutions of sodium thiosulfate, sodium sulfite, and their mixture under standard conditions (without heating of the solution) is considered.
Abstract: The thermodynamic probability of dissolution of noble metals in aqueous solutions of sodium thiosulfate, sodium sulfite, and their mixture under standard conditions (without heating of the solution) is considered. The influence of impurities and catalysts (divalent copper, elemental sulfur, oxygen access into the solution, and ammonia) is evaluated. Theoretical calculations of reaction rates are performed. As a result of theoretical investigations, a conclusion about the usefulness of applying sulfite-thiosulfate solvents of noble metals from ores and concentrates is made.
8 citations
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TL;DR: In this paper, it was shown that at a dilution of 1:200.000, and in the presence of excess sulfuric acid, as little as 0.2 μg nitrate ion forms a yellow color with chroniotropic acid.
Abstract: At a dilution of 1:200.000, and in the presence of excess sulfuric acid, as little as 0.2 μg nitrate ion forms a yellow color with chroniotropic acid. Interfering colors due to nitrites and oxidizing agents are eliminated by previous treatment of the test sample with sodium sulfite, sulfuric acid, and sulfamic acid.
8 citations
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04 Jul 2012
TL;DR: In this article, a method for respectively leaching copper and cobalt from a copper and a cobalt concentrate is presented, which comprises the following steps of: (1) ammonia leaching: adding the cobalt and the copper elements into bottom water, adding ammonium carbonate according to a molar ratio that the ammonium carbate to the copper element in the concentrates is 1:4-12.
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.
8 citations