SIMULTANEOUS DETERMINATION OF URANIUM(VI) AND THORIUM(IV) IONS WITH CARMINIC ACID BY THE PARTIAL LEAST-SQUARES (PLS-1 AND PLS-2) METHODS

Two multivariate calibration methods, partial least squares types 1 an d 2 (PLS-1 and PLS-2) have been applied to the simultaneous determinat ion of U(VI) and Th(IV) ions as complexes with carminic acid by visibl e absorption spectrophotometry. The results obtained by application of different chemometric approaches are discussed. No significant advant ages were found between the methods. The proposed methods were applied satisfactorily to the determination of these ions in synthetic soluti ons simulating sulfuric acid leach solutions obtained from uranium-tho rium ores.