2023 atomic spectrometry update – a review of advances in X-ray fluorescence spectrometry and its special applications

Abstract

The utilisation of SR sources has significantly enhanced the analytical capabilities of XRF spectrometry techniques. With the latest generation of facilities, SR-XRF spectrometry achieves remarkably high nm-scale resolution with excellent LODs at ppb levels. A noteworthy trend is the increasing use of SR-XRF spectrometry together with other X-ray spectroscopic and imaging techniques. This provides complementary information on elemental speciation as well as structural and morphological characteristics of samples. Sub-μm SR-XRF spectrometry has been extensively applied in diverse fields such as environmental and planetary studies, biomedical research, materials science and cultural heritage investigations. Methods for handling the huge datasets produced by macroXRF spectrometry have become essential for processing and classifying the element distributions collected from the analysis of paintings. Machine-learning-based correlations of element maps have been developed for the automatic identification of patterns as an alternative method of processing macroXRF spectrometry data from cultural heritage samples. The microanalytical capabilities of TXRF spectrometry have led to a steep increase in applications to biomedical problems with successful analyses of minute amounts of samples (ca. 20 mg) of, e.g., blood, placenta and heart tissue. The suspension-assisted preparation of theses samples and of mineralogical materials was improved in many studies by extending the common internal standard calibration with uni- and multivariate approaches. The development of a scan-free grazing-exit XRF spectrometer improved accuracy in the analysis of periodic surface structures. The degree of protonation of different thiol- or hydroxyl-bearing organic monolayers was successfully determined using grazing-incidence XRF and TXRF spectrometries in combination with other techniques.