Pulse radiolysis study of oxidation reactions of sulphacetamide in aqueous solutions

✍ Scribed by Sunil Sabharwal; Kamal Kishore; P.N. Moorthy

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 668 KB
• Volume: 44
• Category: Article
• ISSN: 0969-806X
• DOI: 10.1016/0969-806x(94)90047-7

✦ Synopsis

The one-electron oxidation of sulphacetamide by specific oxidizing radicals such as N;, Br; , Cl;, T12+ and SOT in the pH range 2-9.2 has been studied employing pulse radiolysis technique. The semi-oxidized species formed exhibits a pK, at pH 5.4 indicating the presence of two conjugate acid-base forms whose spectral and kinetic features have been evaluated. Reaction of OH radicals with sulphacetamide resulted in the formation of a transient which in neutral and alkaline solutions decayed by first-order kinetics (k = 1.7 x lo4 s-') to yield the semi-oxidized species. The latter, formed both by decay of OH-adduct, as well as directly, has been observed to react rapidly with the biological antioxidant ascorbic acid (k -1.9 x 105dm'mol-' at pH 9.2) forming the ascorbate radical. The effect of .Wc+sAoxygen on the decay behaviour of the OH-adduct and semi-oxidized species has also been investigated.