Record Details
Field | Value |
---|---|
Title | Radiolysis of succinic acid in water |
Names |
Tanaka, Fred Shigeru
(creator) Wang, Chih H. (advisor) |
Date Issued | 1966-05-12 (iso8601) |
Note | Graduation date: 1966 |
Abstract | The radiolysis of succinic acid in aqueous solutions induced by gamma irradiation from ⁶⁰Co has been studied with respect to the identification and estimation of degradation products. Detailed information on the radiolysis of succinic acid is important in determining what effect two carboxyl groups in the same molecule would have on the reaction mechanisms and products relative to the degradation of the hydrocarbon chain resulting from gamma irradiation. ¹⁴C-labeled succinic acid was employed to facilitate product identification and estimation. In addition, specifically labeled succinic acid-¹⁴C and malic acid-¹⁴C were utilized for the elucidation of reaction mechanisms. The irradiation experiments were performed in both oxygenated and oxygen-free systems. The principal means of identification of the radiolytic products were by paper chromatography and autoradiography, utilizing the technique of co-chromatography. The estimation of each radiolytic product was determined by radiochemical assay using liquid scintillation counting techniques. The oxidation reactions in both oxygenated and oxygen-free systems may possibly follow the same reaction mechanisms, since the degradation products resulting from these reactions are the same in the oxygenated and oxygen-free systems, although the yields are greater in the oxygenated system. The oxidation products identified from the radiolysis of succinic acid were malic, malonic, oxaloacetic, pyruvic, oxalic, mesoxalic, glyoxylic, propionic, acetic, and formic acids, glyoxal, and carbon dioxide. The products of molecular weight greater than succinic acid produced exclusively from radiolysis in the oxygen-free system were 1, 2, 3, 4-butane-tetracarboxylic, 1, 2, 4-butane-tricarboxylic, tricarballylic, glutaric, and adipic acids. The radiochemical yields of the radiolytic oxidation products from specifically labeled succinic acid-¹⁴C were determined to be greater in the oxygenated system than in the oxygen-free system. This fact indicates that oxygen plays an important role in the radio-lytic degradation of succinic acid. The graphical presentation of the degradation of succinic acid and the formation of malonic and malic acids with increasing cumulative dose follow the same course in both oxygenated and oxygen-free systems. However, the radiolytic degradation of succinic acid and the formation of malonic and malic acids were greater in the oxygenated system. The formation of malonic acid from radiolysis of succinic acid aroused considerable interest, since this acid was produced in unusually high yield. Therefore, studies were carried out to elucidate the mechanism for malonic acid formation. The results for radiolysis of ¹⁴C specifically labeled succinic acid indicated that malic acid probably was an intermediate in the formation of malonic acid. In order to verify this result, specifically labeled malic acid-¹⁴C was used in similar irradiation experiments. The results of this experiment indicated that malonic acid formation resulted from C-1 decarboxylation of malic acid followed by oxidation of the intermediate. Several reaction mechanisms were suggested as possible mechanisms for the formation of malonic acid. The most likely mechanism involved OH addition across the double bond of the enol form of oxaloacetic acid, in which decarboxylation of the adduct accompanied by oxidation resulted in the formation of malonic acid. |
Genre | Thesis/Dissertation |
Topic | Radiation |
Identifier | http://hdl.handle.net/1957/47767 |