Slurry sampling fluorination assisted electrothermal vaporization-inductively coupled plasma-atomic emission spectrometry for the direct determination of metal impurities in aluminium oxide ceramic powders

A comparison of slurry sampling electrothermal vaporization and slurry nebulization inductively coupled plasma mass spectrometry for the direct determination of trace impurities in titanium dioxide powder

A comparison of slurry sampling (SS)-ETV-ICP-MS and slurry nebulization (SN)-ICP-MS for direct determination of trace impurities in titanium dioxide powder is made. The particle size effect, matrix effect and analytical characteristics of SSETV-ICP-MS and SN-ICP-MS are compared. The results have shown that SSETV-ICP-MS has a lower particle size effect and matrix effect compared to SN-ICP-MS. The analytical performance of the two methods reveals that SSETV-ICP-MS and SN-ICP-MS have similar relative detection limits (in the nanogram per liter level); however, the former has a lower absolute detection limit than the latter. Although the precision for SSETV-ICP-MS is a little worse than that for SN-ICP-MS, it is still acceptable for real sample analysis. The two methods were successfully applied for the determination of trace impurities in titanium dioxide powder samples with particle sizes of less than 50 nm, but only SSETV-ICP-MS could be applied for the determination of trace impurities in titanium dioxide powder samples with a particle size of 1 microm.

Direct analysis of Al2O3 powders by total reflection X-ray fluorescence spectrometry

A direct analysis procedure for the determination of trace impurities of Ca, V, Cr, Mn, Fe, Ni, Cu, Zn and Ga in Al2O3 ceramic powders by total reflection X-ray fluorescence spectrometry (TXRF) is described. The powders were analysed in the form of slurries containing 1-10 mg mL(-1) of powder. The use of the procedure in the case of powders with differing grain size and for different slurry concentrations was investigated. Three different quantification possibilities were compared, namely the use of Al as a matrix component, the use of Fe as a trace element contained in the sample or of Co added in concentrations of 200 microg g(-1) as internal standard. The homogeneity of elemental distributions in sample layers deposited on the TXRF quartz carriers by evaporating 5 microL of the 10 mg mL(-1) slurries was studied by scanning the 4- to 5-mm-diameter spots of two samples by synchrotron radiation TXRF at Hasylab. For powders with differing graininess but mainly finer than about a few 10 microm, no systematic influence of the grain size on the accuracy of the determinations of Ca, V, Fe, Ni, Cu and Zn could be observed. The measurement precision, however, seemed to be limited by inhomogeneous distributions of the trace elements in the samples as testified by the synchrotron radiation TXRF scans. Detection limits of the developed TXRF procedure for Ca, V, Cr, Mn, Fe, Ni, Cu, Zn and Ga were found to be in the 0.3-7 microg g(-1) range and were shown to increase slightly with the grain size of the samples. Quantification using Al (matrix) as internal standard led to systematically higher values out of the accuracy required, whereas the other two approaches in all cases led to reliable results.