Standardization sodium nitrite

Procedure. Weigh out accurately about 1.5 g of sodium nitrite and dissolve it in 500 mL of boiled-out water in a graduated flask. Shake thoroughly. Place 50 mL of standard 0.1 M cerium(IV) sulphate in a conical flask, and add 10 mL of 2M sulphuric acid. Transfer 25 mL of the nitrite solution to this flask by means of a pipette, and keep the tip of the pipette below the surface of the liquid during the addition. Allow to stand for 5 minutes, and titrate the excess of cerium(IV) sulphate with standard 0.1 M ammonium iron(II) sulphate, using... 

Determine the volume of the standard cerium(IV) sulphate solution which has reacted with the nitrite solution, and therefrom calculate the purity of the sodium nitrite employed. 

Twenty weakly acidic drugs, including niclosamide, were determined by a nonaqueous catalytic thermometric titration method. Catalysis of the anionic polymerization of acetonitrile was used for endpoint indication. The solvent used was a mixture of acetonitrile and dimethylformamide or pyridine, and the titrant was sodium methoxide, potassium hydroxide, tertiary butanol, or tertiary butanol-sodium nitrite. Recoveries, limits of detection and relative standard deviations were tabulated [31]. 

Standardization of 0.1 M sodium nitrite solution with sulphanilamide... 

STANDARDIZATION OF 0.1 M SODIUM NITRITE SOLUTIOIN WITH SULPHANILAMIDE... 

Materials Required Procainamide hydrochloride 0.25 g 2M hydrochloric acid 100 ml potassium bromide 3 g 0.1 M sodium nitrite Vs (dissolve sodium nitrite in sufficient water to produce 1000 ml) Standardization of 0.1 M Sodium Nitrite Vs Dissolve 0.3 g of sulphanillic acid in 50 ml of 2M hydrochloric acid, add 3 g of KBr, cool in ice and titrate with 0.1 M sodium nitrite Vs determining the end-point amperometrically. Each ml of 0.1 N sodium nitrite Vs is equivalent to 17.32 mg of C6H7N03S. 

Standardization of 0.1 M Sodium Nitrite Solution with Sulphanilamide. .. 208... 

The United States Pharmacopoeia describes the following two identification tests for procaine [31]. In one, the infrared absorption spectra of standard and sample in KBr pellets are compared, and require to exhibit maxima only at the same frequencies. In another test, 10 mg of drug is dissolved in 1 mL of water, to which is added 1 drop each of hydrochloric acid and 1 10 sodium nitrite solution. One then adds 1 mL of a solution prepared by dissolving 0.2 g of 2-naphthol in 10 mL of 1 10 sodium hydroxide solution, shakes, and obtains a scarlet-red precipitate as a positive reaction. 

The synthesis of the vinyl antibiotic cefdinir, which starts with the preformed unsaturated nucleus (30-2), illustrates a scheme that builds the almost obligatory aminothiazole in situ as the last step. Acylation of the amino group in (30-2) with 3-bromoacetoacetic acid (30-1) leads to the amide (30-3). Reaction of that intermediate with sodium nitrite proceeds on the activated methylene to form the nitrite as the initial product. This spontaneously tautomerizes to the observed oxime (30-4). Treatment with thiourea, in one of the standard procedures for forming thiazoles, then leads to (30-5). There is thus obtained cefdinir (30-5) [36]. 

For solid samples dispersed in a KBr disc which have a thickness that cannot be precisely measured, an internal standard is used (e.g. calcium carbonate, naphthalene, sodium nitrite). This reference is added in equal quantity to all standards and to the sample. 

At greater than 0.65 mM sodium nitrite, a linear relationship was not observed between the current and concentrations. The minimum concentration for the determination of sodium nitrite was 0.01 mM (signal to noise, 20 reproducibility, 5 %). The current decrease was reproducible within 4 % of relative error and the standard deviation was 0.01 mM in 25 experiments when a sample solution containing 0.25 mM of sodium nitrite was employed. 

Two samples of air are taken and collected m large stoppered bottles of some 7-litres capacity. One sample is admitted through two tubes containing respectively chromic anhydride and powdered manganese dioxide, the second sample through a tube containing chromic anhydride only. They are then shaken with a dilute standard solution of sodium nitrite rendered slightly alkaline, and the nitrite content subsequently determined colorimetrically.3... 

Of the methods for determining lignin in solution based on a specific chemical reaction, that involving nitrosation, the so-called Pearl-Benson method, has found the widest application. In this procedure, reaction of the phenolic units in lignin with acidified sodium nitrite leads to the formation of a nitrosophenol which, upon addition of alkali, is tautomerized to an intensely colored quinone mono-oxime. The absorbance of the latter structure is measured at 430 nm and related to lignin concentration by calibration with a standard lignin. The procedure described below is essentially that developed by Barnes et al. (1963), who modified the original Pearl-Benson method (Pearl and Benson 1940) to improve its sensitivity. 

Subert, J. Drug analysis. VI. Studies of conditions for dia-zotizing titrations of drugs with potentiometric indication and standardization of a volumetric sodium nitrite solution. Farm. Obz. 1981, 50, 273-278. 

Amyl nitrite, sodium nitrite, and sodium thiosulfate are commercially available in standard doses in the Pasadena Cyanide Antidote Kit. This kit is not widely distributed in Department of Defense medical channels. No antidote kits are provided to naval personnel far forward. However, should a person be exposed to a lethal dose of the agent and not receive therapy immediately, death is certain. 

A colorimetric method for microdetermination of sulfonamides based on diazotization of the drug with sodium nitrite and hydrochloric acid has been reported (59). The diazonium salt is then coupled with 8-hydroxyquinoline in alkaline medium and the absorbance of the developed color measured at its maximum wavelength. A similar method involves diazotization and coupling of the sulfonamide with indole in alkaline solution to form an intense yellow azo dye which exhibits maximum absorption at 449 nm. Beer s law is obeyed over the concentration range 1-32 /ig/ml with a relative standard deviation of less than 2% (60). The reaction of sulfonamides with chloramine-T in sulfuric acid gives a yellow product which is suitable for the determination of sulfonamides in different formulations. It has an accuracy similar to that of the Bratton and Marshall method (61). 

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