This paper summarizes the effects of irregular shape on the results of a quantitative X-ray fluorescence (XRF) micro-analysis. These effects become relevant when an XRF analysis is performed directly on an investigated material. A typical example is XRF analyses of valuable and historical objects whose measurements should be performed non-destructively and non-invasively, without taking samples. Several measurements and computer simulations were performed for selected metallic materials and shapes to evaluate the accuracy and precision of XRF. The described experiments and the corresponding Monte Carlo simulations were related to the XRF device designed and utilized at the Czech Technical University. It was found that the relative uncertainty was typically about 5-10% or even higher in quantitative analyses of minor elements due to irregular shapes of surfaces. This must be considered in cases of the interpretation of XRF results, especially in the cultural heritage sciences. The conclusions also contain several recommendations on how to measure objects under hard-to-define geometric conditions with respect to reduction in the surface effect in quantitative or semi-quantitative XRF analyses.

Department of Dosimetry and Application of Ionizing Radiation Faculty of Nuclear Sciences and Physical Engineering Czech Technical University Prague Břehová 7 11519 Prague Czech Republic

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Moioli P., Seccaroni C. Analysis of art objects using a portable X-ray fluorescence spectrometer. X-ray Spectrom. 2000;29:48–52. doi: 10.1002/(SICI)1097-4539(200001/02)29:1<48::AID-XRS404>3.0.CO;2-H. DOI

Manter M., Schreiner M. X-ray Fluorescence Spectrometry in Art and Archaeology. X-ray Spectrom. 2000;29:3–17. doi: 10.1002/(SICI)1097-4539(200001/02)29:1<3::AID-XRS398>3.0.CO;2-O. DOI

Creagh D.C., Bradley D.A. Radiation in Art and Archeometry. 1st ed. Elsevier; Amsterdam, The Netherlands: 2000. p. 285.

Cechak T., Gerndt J. Analysis of fresco paintings by X-ray fluorescence method. Radiat. Phys. Chem. 2001;61:717–719. doi: 10.1016/S0969-806X(01)00385-1. DOI

Aloupi E., Karydas A.G. Pigment analysis of wall paintings and ceramics from Greece and Cyprus. The optimum use of x-ray spectrometry on specific archaeological issues. X-ray Spectrom. 2000;29:18–24. doi: 10.1002/(SICI)1097-4539(200001/02)29:1<18::AID-XRS397>3.0.CO;2-5. DOI

Cox G.A., Pollard M. X-Ray Fluorescence Analysis of Ancient Glass: The Importance of Sample Preparation. Archaeometry. 1977;19:45–54. doi: 10.1111/j.1475-4754.1977.tb00925.x. DOI

Sándor Z., Tölgyesi S. Qualitative and quantitative analysis of medieval silver coins by energy dispersive X-ray fluorescence method. J. Radioanal. Nucl. Chem. 2000;246:385–389. doi: 10.1023/A:1006755414703. DOI

Janssens K., Vittiglio G. Use of Microscopic XRF for Non-destructive Analysis in Art and Archaeometry. X-ray Spectrom. 2000;29:73–91. doi: 10.1002/(SICI)1097-4539(200001/02)29:1<73::AID-XRS416>3.0.CO;2-M. DOI

Milazzo M. Radiation applications in art and archaeometry: X-ray fluorescence applications to archaeometry. Possibility of obtaining non-destructive quantitative analyses. Nucl. Instrum. Methods Phys. Res. B. 2004;213:683–692. doi: 10.1016/S0168-583X(03)01686-0. DOI

Bonizzoni L., Maloni A. Evaluation of effects of irregular shape on quantitative XRF analysis of metal objects. X-ray Spectrom. 2006;35:390–399. doi: 10.1002/xrs.926. DOI

Bos M., Vrielink J.A.M. Non-destructive analysis of small irregularly shaped homogenous samples by X-ray fluorescence spectrometry. Anal. Chim. Acta. 2000;412:203–211. doi: 10.1016/S0003-2670(00)00771-6. DOI

Trojek T. Reduction of surface effects and relief reconstruction in X-ray fluorescence microanalysis of metallic objects. J. Anal. At. Spectrom. 2011;26:1253–1257. doi: 10.1039/c0ja00187b. DOI

Trojek T., Čechák T. Monte Carlo simulations of disturbing effects in quantitative in-situ X-ray fluorescence analysis and microanalysis. Nucl. Instrum. Methods Phys. Res. A. 2010;619:266–269. doi: 10.1016/j.nima.2009.11.079. DOI

Šmit Ž., Prokeš R. Parametrization of a tabletop micro-XRF system. X-ray Spectrom. 2019;48:682–690. doi: 10.1002/xrs.3102. DOI

Sherman J. The theoretical derivation of fluorescent X-ray intensities from mixtures. Spectrochim. Acta. 1955;7:283–306. doi: 10.1016/0371-1951(55)80041-0. DOI

Trojek T., Čechák T. Use of MCNP code in energy dispersive X-ray fluorescence. Nucl. Instrum. Methods Phys. Res. B. 2007;263:72–75. doi: 10.1016/j.nimb.2007.04.063. DOI

Trojek T., Bártová H. Calibration of Handheld X-ray Fluorescence Spectrometer for Identification and Semi-quantitative Analysis of Objects with Stratified Structure. Radiat. Phys. Chem. 2019;155:310–314. doi: 10.1016/j.radphyschem.2018.08.004. DOI

Trojek T. Iterative Monte Carlo procedure for quantitative X-ray fluorescence analysis of copper alloys with a covering layer. Radiat. Phys. Chem. 2020;167:108294. doi: 10.1016/j.radphyschem.2019.04.044. DOI