Analysis of hypochlorite

Acridine-9-carbaldehyde (24%) is one of several products formed from the oxidation of 5//-dibenz[A/]azepine with tert-butyl hypochlorite in dichloromethane at — 70 C.229 The reaction is even more complex in the presence of silver(I) trifluoroacetate, and an analysis of the reaction mixture by GC-MS techniques reveals the presence of eleven products, the major ones being acridine (37%), an unidentified 5//-dibenz[/ ,/]azepinecarbaldehyde (23%) and acridine-9-carbaldehyde (9 %). 

After completing our analysis of the effects of the dominant equilibrium, we may need to consider the effects of other equilibria. The calculation of [H3 O ] in a solution of weak base illustrates circumstances where this secondary consideration is necessary. Here, the dominant equilibrium does not include the species, H3 O, whose concentration we wish to know. In such cases, we must turn to an equilibrium expression that has the species of interest as a product. The reactants should be species that are involved in the dominant equilibrium, because the concentrations of these species are determined by the dominant equilibrium. We can use these concentrations as the initial concentrations for our calculations based on secondary equilibria. Look again at Example for another application of this idea. In that example, the dominant equilibrium is the reaction between hypochlorite anions and water molecules H2 0 l) + OCr(c2 q) HOCl((2 q) + OH ((2 q) Working with this equilibrium, we can determine the concentrations of OCl, HOCl, and OH. To find the concentration of hydronium ions, however, we must invoke a second equilibrium, the water equilibrium 2 H2 0(/) H3 O (a q) + OH (a q)... 

It was found that the concentration of total oxidants measured in the off-gas from the hypo unit varied with process conditions. Precise analysis of the off-gas showed that under certain conditions chlorine dioxide is formed in the reaction step where the hypochlorite concentration is approximately 160-180 g l-1. In the sections below formation of chlorine dioxide in the hypochlorite unit is discussed with regard to process conditions and peak load of the feed stream. In essence, the emission of chlorine dioxide can be reduced to nearly zero by using a scrubber in which the chlorine dioxide reacts with hydrogen peroxide. 

Economic analysis of designs at lower natural hypochlorite strengths equally show potential investment benefits. They are, however, much less significant than the batch and high concentration cases described above. While an economic case can be made for retrofitting an in-loop reactor to a system that already has an end-of-pipe treatment system based on payback, it is not always clear that this is a better option than an end-of-pipe hybrid system as described earlier in the chapter. For a particular system the optimum solution is often as much a function of the required expenditure on the heat exchangers as it is the relative cost of the reactor options. 

Analysis of the Mechanisum of Deterlorationof Asymmetric Cellulose Acetate Membrane by Sodium Hypochlorite... 

The structure analysis of nitrites, however, shows that they contain isolated NO " groups in complexes of trivalent metals, e.g. in the alkali aluminates (KA102) that have the same bruto composition as the nitrites, the coordination, indeed, is higher. Here the AI3 ions are surrounded by six oxygen ions, a coordination number that is as to be expected for a really ionic compound. Hypochlorites ACIO, chlorites AC102, chlorates AG103, sulphites A2S03, etc., all have coordination numbers that are smaller than those to be expected in ionic compounds. 

Another concurrent factor not considered in the risk analysis was the toxicology of residual amounts of the disinfectant species including hypochlorous acid and chloramines related to chlorine that would normally be present as residuals in chlorinated water. The in vivo toxicology of hypochlorite now indicates the formation of haloforms and halonitriles and thus additional risks (34). 

Analysis When it is known that a chlorite is the only active oxidg agent present, it is easily determined by titration of the iodine liberated from KI in an acidified soln. A chlorite does not liberate iodine until the soln is acidified this serves as a qualitative distinction from a hypochlorite. The quantitative analysis of a soln contg chlorite 8c hypochlorite requires detn of the total oxidg power. Hypochlorite is detd on a separate sample by addg an excess of Na arsenite, after making certain the soln is alk. This "soln is saturated with... 

MW Dong, JR Gant. High-speed liquid chromatographic analysis of amino acids by post-column sodium hypochlorite-o-phthalaldehyde reaction. J Chromatogr 327 17-25, 1985. 

Tsai, C.T., C.T. Kuo, and S.T. Lin. 1999. Analysis of organic halides in hospital waste sludge disinfected using sodium hypochlorite (NaOCl). Water Res. 33 778-784. 

Onodera et al. [8] examined the applicability of isotachophoresis to the identification and determination of chlorinated mono- and dicarboxylic acids in chlorinated effluents. Four electrolyte systems for the separation of acids were evaluated. The potential unit values in each system were determined for the chlorinated acids. A mechanism for the reaction of phenol with hypochlorite in dilute aqueous solutions is suggested, based on results from the isotachophoretic analysis of diethyl ether extracts taken from phenol treated with hypochlorite. 

Analysis of Osmiridium.2—Osmiridmm, in a finely divided condition, is intimately mixed with four times its weight of sodium peroxide and added to fused sodium hydroxide in a nickel crucible. On treating the product with water and washing the residue with sodium hypochlorite solution, a solution is obtained which holds all the osmium and ruthenium as alkali osmate and ruthenate respectively, and some of the iridium as iridate. 

In SPE, the NH4+ in the sample is converted to indophenol following a variation of the phenol/hypochlorite method described above for measuring NH4+ concentrations. The indophenol solution is passed through an octadecyl C18 SPE column that binds the indophenol to the resin. The indophenol is then eluted with methanol. The recovery of NH4+ with this method is generally low, less than 30% (Sehner and Sorensson, 1986). Alternately, the indophenol can be extracted into dichlor-omethane (Dudek et al., 1986) recovery is not explicitly stated but the blank calculations appear to assume it is quantitative. Recently the SPE approach has been modified to allow the analysis of low N seawater (0.01—0.1 pM) samples to be analyzed using a GC-MS (Clark et al, 2006). 

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