Total-Reflection X-Ray Fluorescence Spectrometry (TXRF): Application to Elemental Profiles on Trace Evidence and Microsamples

Total-Reflection X-ray Fluorescence spectrometry has been available as commercial instrumentation for the past few years. Since that time investigations and research has been conducted on the application of the technique particularly to problems involving micro samples such as in conservation and forensic analysis.Elemental characterization of paint pigments, glass samples, textile fibers and liquid inclusions have been performed.The EXTRA IIA TXRF spectrometer has inherent potential for the microanalysis. This instrumentation allows for simultaneous multi-element analysis for elements Phosphorus to Uranium with instrument detection levels (IDLs) less than or equal to 10 picograms for 50 of these elements.Qualitative and semi-quantitative screening are possible with little sample preparation, while dissolved samples result in improved accuracy and precision with a dynamic range of five orders of magnitude without multiple dilutions.This paper briefly reviews the principal and theory of TXRF, the operation of this instrument and its advantages over other quantitative elemental analysis techniques for these types of samples. Data demonstrating the comparable results obtained with the EXTRA IIA to that of ICP, AA, and NAA methods on samples supplied as proficiency tests will be presented. No difference in the quantitative results was exhibited between the reference and test data at a 95% confidence level.