Simultaneous Determination of Hydrogen Peroxide and Organic Hydroperoxides in Water
Titel:
Simultaneous Determination of Hydrogen Peroxide and Organic Hydroperoxides in Water
Auteur:
Gere, Erzsebet P. Berczi, Barna Simandi, Peter Wittmann, Gyula Dombi, Andras
Verschenen in:
International journal of environmental analytical chemistry
Paginering:
Jaargang 82 (2002) nr. 7 pagina's 443-450
Jaar:
2002
Inhoud:
The kinetics of the reactions of H 2 O 2 and of methyl, ethyl, tert -butyl, and cumene hydroperoxides with I - were investigated in the presence and absence of molybdate as catalyst. These results were utilized to develop an analytical method for the simultaneous determination of H 2 O 2 and organic hydroperoxides in aqueous solutions. The total amount of H 2 O 2 and organic hydroperoxides can be determined by the spectrophotometric measurement of $ {\rm I}_3^ - $ formed quantitatively during 30 min of heating at 60°C. Catalase selectively decomposes H 2 O 2 in solutions containing organic hydroperoxides. The total amount of the latter can therefore be determined iodometrically after H 2 O 2 decomposition. In the oxidation of leuco crystal violet to crystal violet by H 2 O 2 and organic hydroperoxides, horseradish peroxidase exerts similar activities in the reactions involving methyl and ethyl hydroperoxides and H 2 O 2 , but its activity is much lower with tert -butyl and cumene hydroperoxide. It was observed that acetate buffer is unsuitable for pH adjustment in this type of hydroperoxide determination in consequence of the slow oxidation of the dye in the blank solution.