Peracetic acid determination

A fresh sample of this 40% peracetic acid contains about 1.54 equivalents, or 0.77 mole, of peroxide per 100 ml. of solution, corresponding to 1.34 equivalents per 100 g. The concentration can be determined by treating the peroxide solution with potassium iodide and titrating the liberated iodine with standard sodium thiosulfate. The concentration of peroxide in peracetic acid decreases somewhat on long standing and should be checked before the peracetic acid is used. The yield of diacetate is lowered if the concentration of the peroxide is less than 1.0 equivalent per 100 g. of peracetic acid. The total amount of peroxide used should be 2.4 moles, or 4.8 equivalents, for each mole of iodo-benzene. 

Satisfactory 40% peracetic acid is obtainable from Buffalo Electrochemical Corporation, Food Machinery and Chemical Corporation, Buffalo, New York. The specifications given by the manufacturer for its composition are peracetic acid, 40% hydrogen peroxide, 5% acetic acid, 39% sulfuric acid, 1% water, 15%. Its density is 1.15 g./ml. The peracetic acid concentration should be determined by titration. A method for the analysis of peracid solutions is based on the use of ceric sulfate as a titrant for the hydrogen peroxide present, followed by an iodometric determination of the peracid present.3 The checkers found that peracetic acid of a lower concentration (27.5%) may also be used without a decrease in yield. The product was found to be sufficiently pure, after only one recrystallization from 60 ml. of petroleum ether (b.p. 40-60°) and cooling overnight to —18°, to be used in the next step. 

Wheat flour, dibenzoyl peroxide determination, 698, 701 Workplace air benzoyl peroxide, 701 peracetic acid, 699 Wurster s reagent, hydroperoxide determination, 678, 684... 

The reaction between acetaldehyde and peracetic acid in the presence of copper or with no metal acetate present was studied by the method of Bawn and Williamson (4) using Methods I and II (see below) for determining peracetic acid and total peroxide, respectively. 

Peroxide Determinations. Bawn and Williamson report two iodometric procedures for determining peracetic acid (Methods I and III below) and one method for determining total peroxide (4) (Method II). Bawn and Jolly report another method for total peroxide (5) (Method IV below). The difference between total peroxide and peracetic acid is assumed to be acetaldehyde monoperacetate (AMP). Each method was tested in our preliminary studies. Method III is preferred for peracetic acid because the results are more reproducible. In Method I a large blank titration was always observed, while in Method III the blank titration was very small. Method IV is preferred for total peroxide because it seems to be more sensitive to total peroxide and less sensitive to water content of the acetic acid solvent. 

A possible mechanism for manganese (III) catalysis would be the stepwise formation of a manganese (III) complex with two peracetic acid molecules which then would decompose in the rate-determining step. The formation of this complex should be rapid since it is known that manganese (III) complexes are substitution labile (6, 23) ... 

For peracetic acid and oxygen atom series ST /T" is approximately 2. The difference in the activation energies for any two olefins is twice as large for epoxidation by peracetic acid as it is for addition of oxygen atoms. Temperature dependence of the rate constants has not been determined for the other reaction series in Figure 8. 

The reaction mechanism for A-oxidation by performic acid has been studied by AMI calculation methods.174 The iminium salt A-mcthyl-3,4-dihydroisoquinolinium p-toluenesulfonate has been used to catalyse the oxidation of the azo dye calmagite by peracetic acid. The mechanism at pH 10 involves peracid oxidation of the quinolinium ion to form an oxaziridinium salt, which then acts as an oxygen transfer agent for oxidation of cahnagite.175 The presence of lithium salts affects the course of the reaction determining the formation of benzoyl peroxide and benzoic acid as final products in the oxidation of benzaldehyde by perbenzoic acid.176,177... 

The stereochemistry of compounds 8, 9, and 10 was determined by NOE spectroscopy. It has been reported 20a that the methyl and pentyl adducts of levoglucosenone (2) when oxidized by peracetic acid give y-lactones that correspond to lactone 10, but no intermediate formates were reported. 

The crystal structure of Compound I has been determined after its generation by reaction of ferric HRP with peracetic acid [28]. The high reactivity of Compound I... 

Approximately 40% peracetic acid in acetic acid is available (Becco Chemical Division, Food Machinery and Chemical Corporation, Buffalo 7, New York). Sodium acetate is added to neutralize a small amount of sulfuric acid which is present in the commercial product. The peracetic acid concentration should be determined by titration.2 The peracetic acid solution used by the submitters contained 0.497 g. (0.00655 mole) of peracid per... 

The peracetic acid content of the reagent may be determined by adding an aliquot to an equal volume of ice and water and titrating first with ceric sulfate solution until the orange color of the ceric ion remains (to eliminate hydrogen peroxide) and then adding potassiiun iodide and titrating with standard sodium thiosulfate solution. 

The extent of peracetic acid consumption can be determined by titration of an aliquot as described in Note 4. 

In the conventional technology, the temperature range in production is 40 °C-60 °C due to safety reasons. Peracetic acid decomposes to oxygen and acetic acid in higher temperatures. However, higher temperature and higher initial concentrations of raw materials at optimal molar ratios increase the reaction rate and would lead to shortened residence time (Swem, D., 1970). Therefore, the major limits are identified for the conventional process in the reaction step, which is both rate-determining and equilibrium-limit. Moreover, it is also a bottleneck step in terms of inherent safety due to the exothermic reaction, the easier decomposition of peracetic acid and explosion. 

Preparation. The reagent is prepared by stirring 0.1 mole of iodobenzene in a bath at 30° during dropwise addition of 0.24 mole (0.48 equiv.) of commercial 40% peracetic acid. The product crystallizes and is collected after cooling and washed with water. The purity is determined by treatment of a sample with dilute... 

Similarly, for an oxidant that contains an indirectly activated oxygen, the preparation method can always be used to determine the oxidant. For example, lodosylbenzene (PhlO), a common oxidant, is made by treatment of the hyperva-lent iodine reagent PhI(OAc)2 with sodium hydroxide. The diacetate is made from the action of peracetic acid and acetic acid on iodobenzene. Thus, the iodosylben-zene oxidant can be traced to hydrogen peroxide, which is used to make the peracetic acid. 

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