Electrochemical methods hydrogen peroxide determination

Oxidation indices, 656-72 peroxide determination, 762-3 peroxide value, 656, 657-64 colorimetry, 658-61 definition, 657 direct titration, 657 electrochemical methods, 663-4 IR spectrophotometry, 661-3 NIR spectrophotometry, 663 UV-visible spectrophotometry, 658-61 secondary oxidation products, 656, 665-72 tests for stability on storage, 664-5, 672 thermal analysis, 672 Oxidative amperometiy, hydroperoxide determination, 686 Oxidative cleavage alkenes, 1094-5 double bonds, 525-7 Oxidative couphng, hydrogen peroxide determination, 630, 635 Oxidative damage... 

Kadnikova and Kostic have described biocatalytical oxidation of ABTS by hydrogen peroxide using HRP encapsulated in sol-gel glass [47]. Campanella and coworkers have recently presented an electrochemical method for the determination of antioxidant capacity using a biosensor [48]. 

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. 

Mayer determined acetylcholine and choline by enzyme-mediated liquid chromatography with electrochemical detection [195]. The two compounds were separated by passing the eluted fractions through a post-column reactor containing immobilized Acetylcholineesterase and choline oxidase. In the presence of either compound, the dissolved oxygen was converted into hydrogen peroxide, which was detected amperometrically at a platinum electrode. This method was used to determine choline in rat brain homogenates. 

In the second part of the work, the authors used only GIOD due to the simplicity of detecting hydrogen peroxide electrochemically. To determine MSG, the same FIA system is used, and after its optimization, the method is applied to the previous food samples and, in addition, to apple, orange, and tomato juice. 

Hydrogen peroxide, H2O2, together with organic peroxides, is involved in a number of biological pathways, where this molecule is frequently monitored, but also plays an important role in many industrial processes. Last but not least, the environmental importance of (di)oxygen, O2, is obvious and does not need any special comment, perhaps, a remark that, in envirramiental determinations by electrochemical methods, the respective procedures are predominantly dealing with its determination in water samples. 

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