IODOMETRIC DETERMINATION OF 2-THIOCYTOSINE

A new method for determination of 2-thiocytosine using the reaction wi th iodine in a neutral and an alkaline medium is presented. In the vol umetric titration in phosphate buffer (pH 7) and with starch as an ind icator, the determinability range is 50-1000 mu mol (6.35-127 mg). In alkaline medium with potentiometric end-point detection the determinab ility range is 10-250 mu mol (1.27-31.8 mg). In coulometric titration using the biamperometric end-point detection 0.1-10 mu mol (0.0124-1.2 7 mg) of 2-thiocytosine were successfully determined. The relative sta ndard deviation for ail applied techniques was below 1%.