Determination of zirconium and niobium in their joint presence with picramine-epsilon

The possibility was shown of photometric determination of zirconium and niobium in their joint presence without preliminary separation from the picramine-epsilon (2,4-dinitrophenol - (6 - azo - 2) - 1 - naphtol - 3,8 - desulfoacids). The planning method of multifactor extreme experiment was used to obtain optimum conditions for element determination. The best results were obtained in 3N HCl; summary concentration of metals shouldn't exceed 55 mg/25 ml. It was found, that niobium in the presence of zirconium can be determined at the Nb:Zr (<=) 1:5 ratio, and zirconium in the presence of niobium at Zr:Nb (<=) 1:5 ratio with variation coefficient up to 10%