DETERMINATION OF FE, NB AND SI IN TITANIUM(IV) OXIDE WHITE PIGMENTS BY AAS USING MULTIVARIATE LINEAR CALIBRATION METHODS

Models for the quantitative determination of Fe, Nb and Si in titanium (IV) oxide white pigments by flame atomic absorption spectrometry (AA S) are described. For the models two multivariate linear calibration t echniques have been used: principal component regression (PCR) and par tial least squares (PLS1). Absorbances measured at wavelengths for ele ments present in solution have been considered as independent (x) vari ables, while the concentrations of elements (or their oxide) to be det ermined have been taken as dependent (y) variables. The results obtain ed by the models do not differ significantly (alpha = 0.05) from those achieved by the XRF method checked in advance by another independent method, the neutron activation analysis (NAA).