Application of SRIXE and XANES to the determination of the oxidation state of iron in prostate tissue sections

Normal prostate and cancerous prostate tissue sections were analyzed using synchrotron radiation-induced X-ray emission and X-ray absorption near-edge structure (XANES) at the X-26A microprobe beam line located at the National Synchrotron Light Source, Brookhaven National Laboratory, USA. In both measurements, a monochromatic beam of size of 16 x 14 mum(2) was applied. Two-dimensional scans of selected areas of non-cancerous and cancerous tissue sections were performed in order to obtain the distributions of various trace element concentrations. The XANES spectra were recorded for selected points containing high concentrations of iron. These measurements were performed with the aim of determining the oxidation state of iron. It was found that the iron concentration was much higher in the cancerous sections of the analyzed tissues than in the non-cancerous sections. From the results of XANES spectra analysis, iron in cancerous prostate tissue sections mostly occurs in the +3 oxidation state. (C) 2003 Elsevier B.V. All rights reserved.