Direkte spektroskopische Analyse von Spurenelementen in ZnSe-Proben im rotierenden Gleichstrombogen unter Anwendung eines homogenen Magnetfeldes und von Zusatzsubstanzen

Summary An emission spectroscopic method was developed for the simultaneous determination of the trace elements Ag, Al, Cr, Cu, Fe, Ga, In, Mg, Mn, Ni, Pb and Ti in ZnSe samples. The sample to be analysed (about 10 mg) is vaporized directly from the anode and excited by a rotating d.c. arc using a homogeneous magnetic field. The influence of elements with lower ionization potential on the plasma was investigated, too. These additives (NaCl, KCl) were introduced into the plasma by means of a wick electrode (cathode). The calibration is carried out on the basis of mixtures of oxides of the trace elements with spectroscopically pure ZnSe powder. Analytical detection limits of the trace elements investigated were in the region of ppm and sub-ppm corresponding to absolute amounts of 10 ng and lower.