Coulometric Microdetermitiation of Surface Water on Various Metals and Glasses and of Hydrogen in Beryllium Metal

The water adsorbed on the surface or combined with the oxide film of metals influences the results of analyses of gases in metals. The effect of the surface treatment of steel samples on the results of oxygen determinations was investigated by Kammori et al.(1) The same effect on the determination of hydrogen in aluminium was also reported by Goto et al.(2) In these investigations, however, the water adsorbed on the surface of steels was estimated from the fluctuation in the analytical values of total oxygen in the samples whose surfaces were treated by various methods(1), and the water on aluminum was analyzed by the hydrogen determination of the sample in which hydrogen had been previously extracted. The water itself evolved from the original sample has not been determined directly because of the extremely small amount of water beyond the sensibility of the analysis. In the preceding papers, however, the present authors proposed a method for the microdetermination of water on the surfaces of weights(3) and of hydrogen in metals(4). The microamount of water extracted from a sample into argon carrier was converted to ammonia with sodium amide. The ammonia thus produced was determined with the coulometrically generated hypobromite ion. After its oxidation with copper (II) oxide, hydrogen was determined. Since hydrogen does not react with sodium amide, a selective determination of water in hydrogen is possible by this method when= a mixture of water and hydrogen is extracted from the sample into argon by heating at high temperature. The amounts of surface water for steels and aluminum metals are determined directly by the proposed method after the treatment of the sample surfaces by various methods. Hydrogen and water in beryllium metal and the amounts of water evolved by heating various glasses are also determined by the same method.