Glass Finger Printing Analysis

Micro-XRF, as an analytical tool, combines several features which make it ideal for the investigation of forensic samples. The technique provides simultaneous information on multiple elements down to the trace element level, can be applied under ambient conditions and is non-destructive. The M4 TORNADO table-top micro-XRF spectrometer combines micrometer spatial resolution and element mapping capability with a powerful set of analytical tools for qualitative and quantitative analysis. Glass shard analysis can be carried out quantitative or in a semi-quantitative way according to the ASTM E2926 norm. However, there are several aspects to keep in mind. Above all the information depth of the different elements of the glass can impede both quantitative and semi-quantitative analysis. This is important especially for small particles which can have intricate shapes and it will be hard to identify a good measurement position.

Compositional variations of glass fragments measured with the M4 TORNADO
For a proper use of the ration method described in the ASTM E2926 it is important to select elements with infinite thickness for the analysis sample size range. The diagram shows a calculation of the count rates relative to an infinite sample of a NIST 620 Soda lime glass. Calculation was done with the Bruker Fundametal Parameter code, calculations based on this code can be done online under https://xrfcheck.bruker.com.
Particles of a window glass measured with the M4 TORNADO, showing the enrichment with Sn on the float side of the glass.