Determination of some trace elements in high‐purity tantalum metal by thin‐film x‐ray fluorescence spectrometry

Abstract

The determination of niobium, molybdenum, tungsten, iron and titanium in tantalum metal is described. After dissolution of the metal a d extraction of the tantalum by a chromatographic method using tributyl phosphate, the trace elements are determined on thin-film samples by x-ray fluorescence spectrometry. The thin-film samples are prepared either by spotting the sample solutions directly on to filter-paper or by coprecipitation with indium. The limits of detection on the thin film are 0.05-0.7 pg, depending on the element being measured.

Specimen preparation in x‐ray fluorescence analysis of materials and natural objects

“…When determining Co, Ni and Fe in titanium alloys, these elements were coprecipitated with In(OH) 3 .203 After separation of tantalum using extraction chromatography, impurities contained in the technical tantalum were coprecipitated with indium(III) oxinate in the presence of tannin. 204 was used as a collector Zr(OH) 4 to coprecipitate hydroxides of Sb, Sn, Bi, Pb, As and Fe. 205 To analyse blood serum206 and natural waters,207 selenium was coprecipitated with iron, cadmium or cobalt pyrrolidinedithiocarbamate and the suspension obtained was Ðltered through a Millipore membrane Ðlter.…”

“…The concentrates obtained were separated from the Ðlters and compacted199, 200,208,209 or placed between two Mylar Ðlms in a special holder.202 In other works, a membrane Ðlter together with the precipitate was pressed between two polyethylene terephthalate Ðlms,203 or the Ðlter with precipitate was dried and covered with a polymer Ðlm. 206 In some cases, 198,204,205 an element in the collector was used as the internal standard for calibration.…”