Spectrographic determination of impurities in ultrapure tungsten and tungsten oxide.
The effects of an external magnetic field and of the diameter of the anode on the spectroscopic line intensity of the impurity elements in ultrapure tungsten and tungsten oxide have been studied. The results obtained are used for the development of a more sensitive method for the determination of these impurities (Mn, Pb, Fe, Ni, Al, Mo, V, Cu, Cr).
Untersuchungen zur gleichzeitigen Bestimmung von Molybdän und Wolfram in Proben mit schwierigen Matrices mit induktiv gekoppeltem Plasma
SummaryInaccurate values are often obtained in the determination of molybdenum and tungsten in difficult complex matrices — ores, processing and metallurgical products. The main reason for this effect is due to spectral interferences. Background equivalent concentrations caused by changes of background nearby the measured spectral line are calculated for the established interferent matrix elements. It is possible with the applied sample treatment to perform successful analyses of samples with very variable matrix composition.
Quantitative spektrochemische analyse mittels des gleichstrom kohlebogens
Abstract A complete description of the “Constant temperature arc” method of quantitative analysis which has been developed in Eindhoven is given, with tables of the empirically determined K -values announced so that they can be checked in other laboratories. The method consists of completely volatilizing 5 mg of a powdered sample in a shallow anodic crater of a carbon arc, with the addition of materials to modify the rate of volatilization if required. The line intensities are calibrated by comparison with selected Fe-lines so as to get comparable analytical results; the calculations required are illustrated by several examples which also indicate the accuracy of the method.