Photometric and Gas-Chromatographic Determination of Hydrogen Peroxide and Peroxybutanoic Acid in Oxidized Butanoic Acid

Abstract

Hydrogen peroxide and (or) peroxy acids are contained in the products of the liquid-phase oxidation of many organic compounds [1][2][3][4]. In addition, these peroxide compounds enter into reaction mixtures formed in the acylation of H 2 O 2 with carboxylic acids H 2 O 2 + RCOOH RCOOOH + H 2 O.(1)These peroxy acids are obtained in situ by reaction (1) and are later used as oxidizing agents in organic synthesis, including the Baeyer-Villiger and Prilezhaev reactions [5].To determine H 2 O 2 and peroxy acids in mixtures with peroxide compounds of other classes, methods are mainly used that are based on the ability of enzyme catalase or sulfur-containing compounds (diphenyl sulfide, dimethyl sulfoxide, etc.) to selectively decompose H 2 O 2 [2, 4, 6-9] or peroxy acids [2, 4, 10-13], respectively. The observed decrease in the total concentration of peroxide compounds is detected by conventional methods, most often, by iodometry [2, 10]. It was proposed that peroxy acids be determined from the yield of a sulfur-containing reagent, sulfoxide and (or) sulfone [11][12][13].H 2 O 2 and peroxy acids are difficult to determine quantitatively by available methods in organic compounds oxidized by molecular oxygen or by a mixture of H 2 O 2 and carboxylic acid, because the composition of the products of these reactions is rather complex. It is known that peroxide and oxygen-containing compounds can distort the results of analytical determinations of the products of liquid-phase oxidation [4]. In particular, it might be assumed that carboxylic acids can affect the results of determining H 2 O 2 and peroxy acids because of the occurrence of reaction (1) and the deactivation of catalase in an acidic medium. At the same time, data on the concentrations of H 2 O 2 and peroxy acids are required both to control the above processes and to study the kinetics and mechanisms of reactions involved in these processes.The goal of this work is to develop a procedure for determining H 2 O 2 and peroxy acids in oxidized butyric acid. EXPERIMENTALButanoic acid of reagent grade was purified by rectification in an argon flow. Chemically pure glacial acetic acid and chlorobenzene of reagent grade were freshly distilled. An aqueous hydrogen peroxide solution (31.2 ± 0.1%; RSD = 0.5% at n = 8 and P = 0.95), N , N -dimethyl-p -phenylenediamine dihydrochloride of analytical grade, chemically pure ammonium iron(II) sulfate (Mohr's salt), chloroform of pharmaceutical purity, BF 3 etherate of reagent grade, and catalase from the Kamenskii Distillery (Ukraine) were used without additional purification. The molecular mass of catalase was taken equal to 250 000 [2]. The method for obtaining peroxydodecanoic acid is reported in [12]. We used a preparation that contained 99.3 ± 0.3% of the peroxy acid.The sought parameters of kinetic equations were calculated by the least-squares method using a program written in Delphi 5.5. The set of differential equations Abstract -Procedures were developed for determining hydrogen peroxide and peroxy acids mixed with pero...