Synchrotron Radiation Induced X-ray Fluorescence analysis was successfully applied to the analyses of meteorites, archaeological objects and animal tissues. Electronic states of Fe and Ti in chondrules of chondrites were clarified by micro-XANES to be Fe2+ and Ti4+. Ancient iron implement (B.C. 3c A.D. 3c) with zoning of rusts was characterized by micro-XANES. Two dimensional chemical state analyses of the sample were made by selective excitation of iron. Trace element analyses of Cu, Zn, Se, and Hg in the brain and kidney of rat, mouse, and guinea pig dosed with alkyl mercury and/or Se were made from a view point of mercury intoxication. Strong correlation between Hg and Cu, Zn, Se was observed by the correlation analysis of the elemental distributions. The XRF imaging also disclosed decrease of Cu and Zn level in cancerous tissues of human kidney compared with normal ones.
Advantages of Synchrotron Radiation (SR) as an X-ray source of X-ray Fluorescence (XRF) Analysis have been demonstrated by many pioneering researchers. The advantages include wavelength tunability, high intensity and high resolution, which allow us to carry out nondestructive multielemental analysis of trace elements. However, practical application of the SR-XRF is still limited in numbers. The authors expected that the application of SR-XRF is most promising in the fields of archaeological objects, geological samples, and biological samples and started the present research projects in 1987. Now we have established the analytical procedures of these samples by SR-XRF that we report a part of our results, which so far we obtained from the analyses of geological samples, archaeological objects and biological samples.
The techniques of chemical state analysis used in this study are based on the following two approaches: one is XANES (X-ray absorption Near Edge Structure) and the other is SIXES (Selectively Induced X-ray Emission Spectroscopy). It is well known that the former technique together with EXAFS has been developed rapidly with the development of intense SR beams. SIXES was recently established by Sakurai et al. It enables us to carry out chemical state mapping by X-ray fluorescence using absorption edge shifts. This method was first applied to practical problems in this study.