Investigations on the use of chemical modifiers for the direct determination of trace impurities in Al2O3 ceramic powders by slurry electrothermal evaporation coupled with inductively-coupled plasma mass spectrometry (ETV-ICP-MS)

The direct determination of trace impurities in Al2O3 ceramic basic powders by ICP-MS using electrothermal evaporation (ETV) with slurry sampling has been investigated. To increase interference-free analyte volatilization, th e use of the palladium-group modifiers (PGM) IrCl3, Pd(NO3)(2), and PdCl2 f or the determination of Ca, Fe, Ga, Mg, Mn, Na, Ni, and V in Al2O3 powders was studied. Their role, which in ETV-ICP-MS and ETV-ICP-OES is to stabiliz e the investigated analyte during the ashing phase, to increase vaporizatio n of the matrix, and to reduce transport losses was investigated. Optimum analysis results were obtained with PdCl2 modifier when 500 ng Pd w as used for a sample weight of 100 mug Al2O3 injected into the ETV. Calibra tion was performed by standard addition with aqueous solutions of the analy tes. The RSDs calculated from triplicate analysis ranged form 5 to 10%. Det ection limits between 0.07 mug g(-1) (Ga) and 1.1 mug g(-1) (Na) were achie ved. The accuracy was proven for the elements Ca, Fe, Ga, Mg, Mn, Na, Ni, a nd V by analyzing an NIST standard reference Al2O3 material (SRM 699) with a middle grain size of 16.4 mum. The analytical method was used for the ana lysis of Al2O3 powder (AKP 30, Sumitomo, Japan) with impurities in the low mug g(-1) range and a middle grain size of 1.1 mum. The results obtained fo r the elements Ca, Fe, Ga, Mg, Nn, Na, Ni, and V were comparable with those obtained by ICP-MS subsequent to conventional decomposition with hydrochlo ric acid at high pressure.