par Lacourt, Alice ;Sommereyns, Ghislaine
Référence Mikrochimica acta, 42, 6, page (604-629)
Publication Publié, 1954-11
Article révisé par les pairs
Résumé : The chromatographic separation and determination of tungsten has been considered in the cases in which it occurs alone in solution or accompanied by chromium, vanadium, molybdenum, and iron. Two different types of chromatographic tests have been studied: usual partition chromatography and tests according to conditions B (different solvents for saturation, development, and contamination). To achieve a precise determination of tungsten and the absence of all interference, the usual partition chromatography must be adopted. The reproducibility of the determination of tungsten in this case is of the order of ±2 to 3% for 10 μg of the separated element. Under the conditions of the test B, the reproducibility of the determination of separated tungsten may be just as good (±3 to 4%) if use is made of conventional references and corresponding diagrams such as we recommend. Otherwise, the stains determined in the usual manner yield a deficit of 14% with respect to the deposited tungsten. In this study, the interfering factors play a predominant role from both the quantitative and qualitative points of view. This is the first time that we have been able to accomplish the determination of individual stains of chromatographed elements, remaining on the spot, of which a portion has been dispersed in the paper during the development. The chromatogram obtained under the separating conditions is much less beautiful since it leads to the migration of only the iron and the molybdenum, but it is this which is recommended to produce a perfect determination of tungsten. In the two cases of chromatography, the excess iron is separated from the tungsten during the development. © 1954 Springer-Verlag.