Calibration of paint and varnish properties: Potentialities using X-ray Spectroscopy and Partial Least Squares

This work presents a method for multivariate calibration of the properties of varnishes and paints, combining X-ray Spectroscopy (XRS) with Partial Least Squares (PLS) data treatment. The potential calibrated property for varnishes was density (calibrated values raging from 0.88 to 0.92 g CM-3 and absolute errors from 0.0014 to 0.055 g cm(-3)). For paints, the potential calibrated property was Stormer viscosity (calibrated values ranging from 72 to 89 KU and absolute errors frorn 0.4 to 8 KU). The information here presented was also promoted by the influence of Compton and Rayleigh effects observed in X-ray spectra. X-ray fluorescence spectra were obtained using an ED- XRF system equipped with a Rh target X-ray tube. The importance of the X-ray scattering region (from 18.00 to 24.00 keV), where Compton and Rayleigh effects occur, were evidenced by the best PLS models and lower error values. With the PLS method and X-ray spectra it was also possible to calibrate the content % (m/m) of two organic elements, C and H. It is important to highlight that the proposed analytical method permitted to save time in the quality control of the studied samples, reducing the generation of residues. (C) 2008 Elsevier B.V. All rights reserved.92213113