A Simplified Chemical Method of Radiation Dosimetry

IN 1949, Day and Stein 1 pointed out that doses of ionizing radiations of the order of 20,000 r. could be measured by estimating the phenols produced in dilute aqueous solutions of benzene. They estimated the phenols colorimetrically using the Folin–Ciocalteu reagent. In this method, the conditions under which the blue colour is developed must be carefully controlled, since its rate of production, maximum intensity and stability depend upon the freshness of the reagent and the p H and temperature of the solution.