Cerimetric Determination of Molybdenum in High Chloride Media Using Molybdenum Blue Reaction

Abstract

A new volumetric method of determining molybdenum in a high chloride media is described. After passage through a Jones reductor the reduced molybdenum is caught under a receiver solution of sodium molybdate whose pH is so adjusted that an equivalent amount of molybdenum blue is formed. The molybdenum blue is then titrated to a colorless equivalence point with standard ceric sulfate solution. The formation of molybdenum blue serves two purposes: the oxidationreduction reaction between Mo(III) and Mo(VI) forms an intermediate oxidation state that is stable against air oxidation and the intermediate oxidation state, molybdenum blue, serves as its own indicator in the titration. The results obtainable by this method are comparable to those obtained by the use of the permanganate method in sulfuric acid. (auth) The fluorescent x-ray determination of tantalum in riobium is described A concentration range of 0.05 to 0.70% is covered The oxide-cellulose pellet is placed in the sample holder and the surface irradiated. The fluorescent x radiation from the pellet is dispersed and the integrated intensity of the analytical line is compared to that of a non- dispersed beam from an external standard. The recorded intensity ratios are referred to an appropriate analytical curve to obtainmore » the tantalum concertration (auth)« less