Potentiometric and thermometric determination of mercaptopyrimidines

Potentiometric and Thermometric Determination of Mercaptopyrimidines Potentiometric and thermometric methods for the determination of several 2- and 6-mercaptopyrimidines are described. Mercapto groups can be titrated as acids in water or in dimethylformamide media. The use of acetic acid as solvent allows titration of the basic pyrimidine nucleus. Thermometric titrimetry is also a valuable procedure for the titration of mercapto groups, either directly with sodium hydroxide or by back-titration with hydrochloric acid after addition of excess of alkali. About 10–25 mg of sample can be determined with an error better than 1%.