Raman Spectroscopic Identification of Uric-Acid-Type Kidney Stone

Abstract

Kidney stones of the uric acid type were examined by Raman spectroscopy. The fingerprint pattern of the Raman spectra of these stones matched those of uric acid better than those of sodium urate. Although the Raman spectra of most stones were masked by the high fluorescence of the stones, with the use of a computer to correct the baseline, the Raman scattering bands became distinct. Uric acid has distinct Raman bands at 472, 562, 627, 784, 885, 999, 1039, 1122, 1234, 1288, 1046, 1499, 1595, and 1652 cm⁻¹. The kidney stones examined also showed these bands, indicating that the stones were the uric acid type. Raman spectroscopy is a useful analytical tool for identifying the composition of kidney stones without much sample preparation.