Refinement of major- and minor-element PIXE analysis of rocks and minerals

Abstract An attempt has been made to assess the accuracy of the particle-induced X-ray emission (PIXE) fundamental parameters with standards approach to quantifying major- and minor-element constituents of silicate glasses and minerals. A deviation from linearity at low energies in the channel-energy calibration relationship was identified as a source of undesired residues in GUPIX-fitting. A correction for this effect was developed using a general-purpose spectrum fitting program and was incorporated in GUPIX. The PIXE spectra of sixteen well-characterized electron microprobe standards were then processed. Complementary electron probe micro-analysis (EPMA) measurements were used to support the comparison of the PIXE results with previous characterizations. Major element concentrations were found to differ on average from literature values as follows: SiO 2 (−0.28 ± 0.12%), Al 2 O 3 (0.72 ± 0.74%), MgO (0.11 ± 0.63%), Na 2 O (−2.6 ± 1.2%), K 2 O (1.1 ± 0.7%), CaO (−0.35 ± 0.37%), TiO 2 (2.5 ± 1.9%), MnO (0.8 ± 4.7%), FeO (0.98 ± 0.93%). These results indicate that major and minor elemental analysis can be achieved with high accuracy using the present Guelph micro-PIXE setup.