DETERMINATION OF TRACE IMPURITIES IN HIGH-PURITY QUARTZ BY ELECTROTHERMAL VAPORIZATION INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY USING THE SLURRY SAMPLING TECHNIQUE

A method has been developed for the determination of 14 relevant trace impurities in high-purity quartz based on ETV-ICP-MS IS using slurry sampling, The ETV device consisted of a double layer tungsten coil, Ex perimental conditions were optimized with respect to the temperature p rogram, the carrier gas Bow, the i.d. of the aerosol tubing, ICP-MS me asurement parameters and internal standardization. Excluding U, calibr ation had to be carried out by the standard additions method because o f non-spectral matrix interferences, For U, simple quantification via calibration curves, recorded with aqueous standards, was possible, The observed interferences also aggravated the background evaluation, whi ch seriously limited the determination of Al and Fe, The method was ap plied to the determination of Al, Ba, Co, Cr, Cu, Fe, Li, Mg, Mn, Na, Pb, Sr, U and Zn in two quartz samples of different grades of purity, The accuracy of the results was checked by their comparison with those obtained by independent methods including instrumental neutron activa tion analysis, The achievable detection limits are between 2 ng g(-1) (Li, U) and 70 mu g g(-1) (Al).