New methods of kinetic determination of niobium and tantalum trace amounts in high purity substances

New techniques of kinetic determination of niobium and tantalum, based on oxidation of o-aminophenol, pyrogallol, gallic acid with hydrogen peroxide in neutral medium in the presence of citrates and tartrates of these metals are suggested. The rate of reagent oxidation has been determined photometrically. Optimum conditions of the element determination have been found. Determination limit of niobium and tantalum calculated according to 3s-criterion is equal to 0.01-0.02 μg/ml. Determination techniques of nx10-5-nx10-7% niobium and tantalum in tetramethoxisilane, hydrofluoric acid and MgCo3xLiF have been developed