EDS and XRF Analysis & Testing Services

eds analysis & xrf analysis and testing

SEM-EDS (Energy-Dispersive X-ray Spectroscopy)

In the scanning electron microscope, electrons interacting with samples cause x-rays to be generated from the atoms present. These x-rays have varying energy depending on the element it came from. Once these x-rays are seen on a silicon detector, amplified, and passed through a multichemical analyzer, the elements can be identified and semiquantified. The elements are essentially identified based on the energies of the x-rays which are emitted from the sample. This is a powerful analytical tool as it can detect most of the elements in the periodic table above an atomic number of 4. Detection limits are in the low percentage range. The method is a surface analytical procedure but particles imbedded in a plastic matrix can be exposed by micro surgical techniques and cross-sectioning.

XRF with an fx X-Ray Tube

This system allows higher intensity and greater sensitivity x-ray fluorescence spectra using the same detector as used in the SEM-EDS instrument. Using appropriate standards least squares quantitative analysis can be obtained in the 100 to 1000 ppm range.

ZAF Correction

Specific factors related to specimen (sample) composition (called matrix effects) can affect the x-ray spectrum developed in an electron microprobe analysis and may have to be corrected for if a precise analysis needs to be performed. These matrix corrections are known as Zaf corrections, referring to the three parts of matrix effects - the atomic number (Z), absorption (A), and fluorescence (F).

Spectra from Digital Images

Spectra can be obtained from any spot, raster area or freehand area in the digital image. Line scans can be obtained for any line drawn through the image with element signal intensity for several selected elements simultaneously.

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