Kieselgelstandards für die Bestimmung von Spurenelementen in pulverförmigen Proben mit leichter Matrix durch Röntgenfluorescenzanalyse

The paper deals with homogeneous magnetic fields and added chemical substances both affecting the spectrochemical results obtained in arc excitation studies. The influence of a homogeneous magnetic field on the total intensity of lines of various analysis elements (Hg, Zn, Ga, Tl) in graphite has been examined. Furthermore, the axial and radial distributions of line intensities in arc plasma were determined. Parameters used were the magnetic field strength (0, 0.01, 0.02, 0.04 T) and the physical data of the analysis elements. It was found that the effect of the magnetic field varies with the ionization potential of the elements involved, their atomic mass and the strength of the magnetic field applied. A non-destructive method of measuring was introduced for studying the effects of a homogeneous magnetic field on the rates of evaporation. The results showed increased evaporation rates in presence of magnetic fields as a function of the evaporation heat of the elements involved. Effects of Ga₂O₃ additive on the line intensities of impurity elements are governed by the Ga₂O₃ concentration and the ionization potential of the elements examined.