Calcium L-edge XANES study of some calcium compounds

The Ca L-3,L-2-edge XANES spectra of six calcium salts have been measured i n both total electron and fluorescence yields using a high-resolution spher ical grating monochromator. The compounds investigated were; CaF2, CaCO3, C aCl2. 2H(2)O, calcium phosphate, calcium glycerophosphate and calcium gluco nate. We find that the fine structure of the Ca L-3,L-2-edges for each comp ound is unique and relates to the local structure of the Ca atom. The impli cations of these results to the study of the structure of calcium binding s ites in systems of biologically interest will be discussed.