During an investigation of the electrochemical oxidation of some pteridines in this laboratory, it became necessary to detect and determine oxamide, an oxidation product . Very few methods have been described for the determination of oxamide. The reported methods generally involve alkaline hydrolysis of oxamide to oxalic acid and ammonia, followed by titration of the acid' or titration of the liberated ammonia' . These methods were unsatisfactory for analysis of our rtiixtures, which contained ureas, amides and other species that are hydrolyzed to ammonia, other volatile bases or organic acids . Investigation showed that oxamide gives a very well-defined polarographic wave in neutral and alkaline solutions which could be used for its analytical determination .
This paper describes a detailed examination of the mechanism of the electrochemical reduction of oxamide and the use of the d .c. polarographic wave for its determination.
EXPERIMENTAL
Chemicals
Oxamide (Matheson, Coleman and Bell), glycolamide (Pfalz and Bauer) and acetonitrile (Mallinckrodt) were used .
Buffer solutions were prepared from analytical reagent-grade chemicals . Water-saturated nitrogen was used for deoxygenation of aqueous solutions . Dried argon saturated with acetonitrile was used for deoxygenation of acetonitrile solutions .