It is important to document your technique! This provides validation for your results to the reader who may have questions about your data, especially if there are possible problems (e.g., interferences, alkali element migration, hydrous material).
- What: chemical compositions by electron probe microanalysis-WDS using Cameca SX51 with Probe for Windows software
- Where: Eugene Cameron Electron Microprobe Lab, UW-Madison Dept of Geology & Geophysics
- Operating Conditions: Accelerating voltage (e.g. 15 keV), Faraday Cup current (e.g. 20 nA). If beam was defocussed (e.g. for glass), give diameter.
- Backgrounds: off-peak backgrounds, or possibly mean atomic number (MAN); if your problem required curved background fit, state that.
- Counting times: e.g., 10 seconds on peak with equal on backgrounds
- Standards: state briefly your standards in general, though if any are special or difficult, include details. E.g., synthetic and natural mineral standards were used.
- Any special treatment or corrections: e.g., interference correction?; mitigation of alkali migration by low current, defocussed beam? or correction for it by "volatile element correction"?; anti-contamination for light elements?
- Non-acquired elements? e.g. for oxygen-bearing phases, was oxygen calculated by stoichiometry? if so, state that, and if variable oxidation state elements (e.g. Fe), state your assumptions.
- Matrix correction: The Armstrong-Love/Scott phi-rho-z (modified from Brown and Bastin) (*) with Henke MACs. Where * is Armstrong, J. T., 1988, Quantitative analysis of silicate and oxide materials: comparison of Monte Carlo, ZAF, and phi-rho-z procedures. Microbeam Analysis, pp. 239-246.
- The assumption for EPMA studies is that you have a flat, well polished specimen. If this is not the case, you need to document. Samples must be conductive, and if not (e.g. silicates) they need to be coated with a conductive film, which is typically evaporated carbon. You can optionally give that information if you wish (though if you were explicitly analyzing for carbon, and using a different coating, you clearly would need to state that).