Oxidation of Citric Acid

In the context of qnalitative and qnantitative determination of citric acid in liquid and solid samples, its decomposition by the oxidation with potassium permanganate [Pg.225]

An alternative analytical method, also based on the oxidation with potassirrm permanganate was introduced in 1895 by Stahr [154] and later developed as qtran-titative proeedrrre by Kimz [155-157]. In Starh s method, citric acid is oxidized to acetone diearboxyUc acid, which reacts with bromine to give precipitate of penta-bromoacetone, Br3CCOCHBr2. [Pg.226]

Similarly as with the Deniges method, Stahr was not the first and this reaction was performed marty years before by French organic chemist Auguste Andre Thomas Cahours (1813-1891). In 1847 he published paper entitled Relatives a Taction du [Pg.226]

Molecttlar oxygen takes part in this reaction and no acetone is formed. Acetone appears only above 60 °C [Pg.227]

With increasing strength of potassirrm permanganate solution and temperatrrre, acetone is oxidized to carbon dioxide. Kuyper suggested that the produced carbon dioxide, if determined manometrically, is a measrrre of citric acid concentration. [Pg.227]

An acidic bromate solution can oxidize various organic compounds and the reaction is catalyzed by species like cerous and manganous ions that can generate 1-equivalent oxidants with quite positive reduction potential. Belousov (1959) first observed oscillations in Celv]/[Cem] during Ce (III) catalysed oxidation of citric acid by bromate ion. Zhabotinskii made extensive studies of both temporal and spatial oscillations and also demonstrated that instead of Ce (III), weak 1- equivalent reductants like Mn(II) and Fe (II) can also be used. The reaction is called Belousov-Zhabotinskii reaction. This reaction, most studied and best understood, can be represented as... [Pg.122]

The phrase laboratory curiosity was an apt characterization of a reaction that first saw the light of day in the late 1950 s1. This reaction - the acidic oxidation of citric acid by bromate in the presence of the dual catalysts bromide and cerium(IV)/(III) - displays oscillations in the concentrations of two component species in the course of proceeding towards completion. Curiosity and skepticism were engendered by oscillation in a homogeneous reaction mixture, even though such observations had been well documented in the past. [Pg.2]

The easily visualized Belousov Zhabotinsky (BZ) reaction is now a classic example of the emergence of temporal and spatio temporal dissipative struc tures in homogeneous chemical systems. The reaction was discovered by Soviet military chemist B. P. Belousov in 1951 when he was studying homo geneous oxidation of citric acid by potassium bromide, KBrOq, in the presence of cerium sulfate Ce(S04)2 as the catalyst for redox processes. In the dissolved mixture of these compounds under certain process conditions, Belousov discovered a time-oscillating synchronous reduction of cerium(4+) ions ... [Pg.258]

Belousov (1959) observed sustained oscillations in the ratio of concentrations of the ceric and cerous ions, Ce(IV)/Ce(III), during the cerium catalyzed oxidation of citric acid by bromate in aqueous sulfuric acid. [Pg.11]

In 1958 B.P. Belousov discovered that the oxidation of citric acid by brornate in the presence of cerium ions does not proceed to equilibrium methodically and uniformly, like most chemical reactions, but rather oscillates with clocklike precision between a yellow and colorless state. See Fig. II.1, p. 50 A.M. Zhabotinskii followed up on Belousov s original observation and in 1964 his first investigations appeared in the Russian journal Biofizika. [Pg.133]

Such transformations appeared regularly in the literature of the time, often as brief reports. Phipson (1862) compared the chemical and biological oxidations of citric acid. Permanganate was the chemical oxidant which produced oxalic acid uncooked putrid beef and boiled beef were the biological agents which yielded butyric acid (Scheme 1.3). It is not surprising that the analysis of these transformations (Scheme 3) should differ from a modern interpretation. [Pg.10]

The Kogan (1930) permanganate procedure, based on the oxidation of citric acid... [Pg.398]

Regarding analytical procedures, and the effect of present iodine in aqueous solutions, a special attention was directed to total and partial oxidation of citric acid by periodic acid [265-277]. Huebner et al. [266] and Courtois [267] observed a slow oxidation of citric acid by sodium metaperiodate NaI04 and by periodic acid HIO4, with the formation of an intermediate acetone dicaiboxylic acid and finally formic acid and carbon dioxide. [Pg.229]

Sabbatani L (1900) Oxidation of citric acid and citrates with potassium permanganate. Atti Accad Sci Torino 35 678-684... [Pg.247]

Kuyper AC (1932) The oxidation of citric acid. Proc Iowa Acad Sci 39 175... [Pg.249]

Barek J, Berka A, Pokorna A (1979) Oxidation of organic substances with manganese(III). XI. Oxidation of citric acid with manganese(lll) sulfate. Coll Czechoslov Chem Comm 44 1134-1145... [Pg.249]

Mehrotra RN, Ghosh S (1963) Kinetics of oxidation of citric acid by ceric sulfate in aqueous sulfuric acid. Z phys Chemie 224 57-64... [Pg.249]

Sen Gupta KK (1964) Oxidation of citric acid in aqueous solution by Ce(IV) ion. J Proc Inst Chem (India) 36 149-151... [Pg.249]

Reddy CS (2007) Homogenous catalysis of manganese(II) in the oxidation of citric acid by acid bromate a novel behaviour of citric acid. Indian J Chem 46A 407-417... [Pg.250]

Kabir-ud-Din, Hartani K, Khan Z (2000) Unusual rate inhibition of manganese(II) assisted oxidation of citric acid by chromium(VI). Trans Met Chem 25 478-484... [Pg.250]

Mali M, Khadaskar SN, Patel NT (2004) Kinetics of chromic acid oxidation of citric acid and tartaric acid (in lemon and tamarind, a comparative study) in acetic-water medium. Asian J Chem 16 811 817... [Pg.250]

Mehrotra RN (1968) Kinetic acidity dependence in certain oxidation reactions. Part III. Oxidation of citric acid by quinquevalent vanadium ion. J Chem Soc B Phys Org 1563-1566... [Pg.250]

Kumar S, Mathur PC (1978) Kinetics and mechanism of oxidation of citric acid by alkaline hexacyanoferrate(III) catalysed by Cu(II) ions. J Inorg Nucl Chem 40 581-584 Lin LL, Liu GG, Lv WY (2012) Simultaneous oxidation of citric acid and reduction of copper ion by TiOj. Adv Mater Res Durnten-Ztlrich 485 253-256... [Pg.251]

Courtois J (1949) Oxidation of citric acid with periodic acid. Ann Pharm Erancaises 7 77-89... [Pg.251]

In the case of acrylamide polymerization initiated by the citric acid/ permanganate system, the oxidation of citric acid leads to a keto-dicarbox-ylic acid, which, upon drastic oxidation, transformed into acetone and carbon dioxide [246]. The mechanism of the redox system is as follows ... [Pg.75]

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