Determination of thiourea, phenylthiourea and allythiourea with iodine

Abstract

A sensitive and accurate titrimetric method for the determination of 5–1000 µg of thiourea and 20–1000 µg of phenylthiourea or allythiourea has been developed. The method is based on the reaction of these compounds with a chloroform solution of iodine in sodium hydrogen carbonate solution, removal of the excess of iodine, followed by the determination of the resulting iodide by the Leipert amplification procedure. The relative errors ranged from –1.9 to 0.3% and the relative standard deviations from 1.3 to 0.2%, depending on the concentration levels.