Sodium chlorite, analysis

Sodium chlorite, analysis of, for preparation of chlorine (IV) oxide, 4 156 Sodium cyanate, 2 88 Sodium diimidothiophosphate, formation of, from thiophosphoryl triamide, 6 112... 

In the AWWA specification standards, technical soHd sodium chlorite should not contain less than 78.0 wt % NaC102. The impurity limits for 80% assay sodium chlorite should not be more than 17.0 wt % sodium chloride, 3.0 wt % sodium carbonate, 3.0 wt % sodium sulfate, and 0.0003 wt % arsenic. The AWWA standards also specify the analysis procedures for all of the chemical components ia the sodium chlorite. 

The exact amount of sodium chlorite required to produce 0.1 g. of chlorine (IV) oxide is determined by analysis. The required amount (about 1.3 g.) of nearly pure, dry, powdered sodium chlorite is placed in a 1-1. flask. The flask is fitted with a chlorine-treated stopper f having inlet and outlet tubes equipped with stopcocks. The inlet tube should extend to the bottom of the flask. The flask is partially evacuated by means of a water pump. The resulting vacuum is partially released with chlorine which is metered by using a chlorine-saturated sodium chloride solution as a metering fluid. Chlorine is used in an amount approximately 100% in excess of the theoretical requirements. The system is then returned to atmospheric pressure by... 

Sodium Chlorite. An accurately weighed sample of about 2.0 g. of sodium chlorite is dissolved in 1 1. of water a 25-ml. aliquot serves as the sample for analysis. Two milliliters of 50 % potassium iodide and 10 ml. of acetic acid are added to the aliquot, and the ensuing reaction is allowed to proceed in the dark for 5 minutes. The liberated iodine is then titrated with 0.1 A standard sodium thiosulfate solution, using starch as an indicator. The equations for the reactions are written below.1... 

The CWM (1 g) is first depectinated by extraction with 0.05 M CDTA at 20°C for 6 h, twice. The insoluble residue is suspended in distilled water (75-100 ml) in a loosely stoppered flask and heated at 70°C. Glacial acetic acid (0.15 ml) and sodium chlorite (0.3 g) are added and the contents stirred for 15 min. The treatment is repeated and the mixture stirred for a further 15 min. To prevent accumulation of chlorine dioxide gas, the contents are continuously flushed with argon. After cooling, the contents are filtered and the residue washed with five bed volumes of distilled water. The filtrate is purged with argon to remove chlorine dioxide, dialyzed, and concentrated to yield the crude chlorite-soluble glycoprotein fraction, and an aliquot is freeze-dried for analysis (yield 80 mg from 1 g dry CWM of runner beans). 

CWM was then extracted sequentially with water at 80 and with ammonium oxalate at 80, delignified with acidified sodium chlorite at 70 , and then further extracted with M and 4M sodium hydroxide. The crude polysaccharide extracts were likewise analyzed for constituent sugars and uronic acid (Table II). In order to obtain defined polysaccharide fractions the following separations were attempted. Polysaccharide fraction A was separated by ion-exchange chromatography on diethylaminoethyl(DEAE)-Sephadex A-50 and the neutral fraction afforded a virtually pure arablnan ( in Scheme 2) after selective precipitation with cetyltrimethylammonium hydroxide (7 ). Linkage analysis by methylation confirmed that this arablnan was of the highly branched type associated with pectins for which the representative, but not unique, structure (J ) may be advanced. 

Halobenziodoxoles l-Chloro-l,2-benziodoxol-3-(l//)-one (88, 2X = O, Y = Cl) can be easily prepared by direct chlorination of 2-iodobenzoic acid [233], or by the oxidation of 2-iodobenzoic acid with sodium chlorite (NaC102) in aqueous hydrochloric acid media [267]. The original X-ray single-crystal analysis of l-chloro-l,2-benziodoxol-3-(l//)-one reported in 1976 was relatively imprecise [268]. More recently, Koser and coworkers reported the single-crystal X-ray structure of a 1 1 complex of l-chloro-1,2-benziodoxol-3-(l/7)-one and tetra-n-butylammonium chloride [262], The primary bond distances at iodine in this compound are consistent with expectations for a X -iodane. In particular, the I—Cl and I—O bond distances of 2.454 and 2.145 A, respectively, are greater than the sums of the appropriate covalent radii and reflect the... 

Household bleach contains sodium hypochlorite, so it is an active, decomposing waste constituent. In water treatment plants, the more expensive chlorine dioxide is sometimes used as disinfectant to avoid any impleasant taste of the water. It is unstable, so is usually prepared in situ by reacting sodium chlorite with chlorine or hydrochloric acid. Thus it is of practical importance to also include the analysis of these species in any water analysis. If ozone is used for disinfection, small quantities of other oxohalides can be formed as by-products during water treatment. The presence of the oxohalides in drinking water can be a high risk so their analysis is also recommended. The tolerable oxohalide content in drinking water is at the ppb level. 

Most likely, the chemical system remains closed, as far as the other components in the silicate phases are concerned, as diagenesis or low grade metamorphism becomes more evident. Although there may be transfer of calcium, it seems, from bulk chemical analysis, that there is no systematic increase in potassium nor decrease in sodium content of argillaceous sediments. The transfer of Na and K is between the two size fractions—clay and coarse fraction—or between phyllosilicates and tectosilicates. Albitization of argillaceous rocks should be a common phenomenon where mixed layered phases are predominant in clay assemblages and especially evident in the illite-chlorite zone. 

Bromate is a disinfection by-product that is produced from the ozonation of source water that contains naturally occurring bromide, whereas chlorite and chlorate are produced as a result of using chlorine dioxide as a disinfectant. Recently, bromate has become the most important inorganic oxyhalide by-product, and its concentration in drinking water has to be controUed. Another chaUenge is seawater, which represents a vay difficult matrix for the analysis of trace ionic constituents, because chloride, sulfate, and sodium are the primary ions and they are presort at extremely high concentrations. " ... 

A number of different ion chromatographic techniques exist for bromate analysis. In method 300.0 (Part B) [20], the U.S. EPA describes the separation of oxyhalides - chlorite, chlorate, and bromate in the presence of mineral acids on lonPac AS9-SC with suppressed conductivity detection. On this stationary phase, adequate separation between bromate and chloride is achieved with the standard eluant mixture of sodium carbonate and sodium bicarbonate if the chloride excess is less than 100-fold. Because in real-world samples the chloride content can easily be 50-100 mg/L, bromate quantification in the concentration range between 1 pg/L and 10 pg/L is impossible under standard conditions. Kuo et al. [21] improved the separation by treating the sample with a cation exchanger in the silver form, through which the chloride content is decreased to a value determined by the solubility of silver chloride in solution ( 0.4 mg/L chloride). 

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