Patent ID: 6344359
Filing Date: 2002-02-05
Classification: G01N

Abstract:
A colorimetric method for the determination of the presence of total vanadium, and of the concentrations of vanadyl and vanadate in a sample, the method comprising:combining a sample suspected of comprising either or both of vanadyl and vanadate with a colorimetric substrate of the formula: â€ƒwhere X and X1 are, independently, halogen substituents; wherein the complex of said substrate provides a differential light absorption for vanadyl and vanadate, in the presence of a solvent that minimizes vanadyl oxidation; reading the absorbance of said sample at a first wavelength that provides a measure of the combined vanadyl and vanadate concentration; reading the absorbance of said sample at a second wavelength that provides a measure of the vanadate concentration; wherein the concentration of total vanadium is proportional to the absorbance at said first wavelength, and the concentration of vanadate is proportional to the absorbance at said second wavelength.