Determination of traces of titanium down to sub-part-per-million levels in molybdenum metal and compounds by ion exchange chromatography/spectrophotometry

• Published in: Analytical chemistry (Washington) Vol. 58; no. 12; pp. 2408 - 2412
• Main Author: Strelow, F. W. E
• Format: Journal Article
• Language: English
• Published: American Chemical Society 01.10.1986
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac00125a012

Traces and up to 10 mg of Ti can be determined in large samples of Mo or Mo compounds (up to 10 g) by cation exchange chromatography with columns containing only 2 or 4 g of AG50W-X4 resin followed by determination using spectrophotometry of the Tiron complex in the presence of complexing agents. Separations are very satisfactory, leaving only between 5-30 mu g of Mo in the Ti fraction when 10 g of MoO sub 3 is present originally. Recoveries of Ti from synthetic mixtures are quantitative and 5 mu g of Ti (0.5 ppm) in 10 g of MoO sub 3 can be determined with a standard deviation of 0.2 mu g (0.02 ppm). Relevant elution curves and results for the analysis of synthetic mixtures and some actual samples are presented and the influences of nitric and phosphoric acid concentrations on the separation are discussed. In addition, a method is presented to avoid excessive catalytic decomposition of H sub 2 O sub 2 , which can interfere with the column separation. 9 ref.--AA