URINARY STONE ANALYSIS BY SMALL-SPOT ELECTRON-SPECTROSCOPY FOR CHEMICAL-ANALYSIS (ESCA)

Small-spot Electron Spectroscopy for Chemical Analysis (ESCA) has been used to study the composition of calcium oxalate and calcium phosphate urinary stones. This technique allows for the identification and location of various inorganic and organic species and provides information about the events leading to stone formation. Unlike other methods, such as scanning electron microscopy and x-ray diffraction, which provide elemental composition and morphological information, ESCA, with its high sensitivity for low Z elements, is also able to detect differences in chemical functionality. The spectra obtained from a urinary stone cross section show changes in chemical composition and functionality of carbon and nitrogen species. Comparison of these spectra with those of standard reference materials has enabled the identification of each detected species.