Application of PLS multivariate calibration for the determination of the hydroxyl group content in calcined silica by DRIFTS

A method based on diffuse reflectance infrared Fourier transform spectrosco py (DRIFTS) was developed for the rapid determination of the hydroxyl group content in calcined silica. Thermogravimetry (TG) was used as a reference method to determine the hydroxyl concentrations. The data pretreatment was performed with orthogonal signal correction (OSC) and it was followed by su bsequent partial least squares (PLS) modelling. The calibration model was v alidated by predicting the hydroxyl content of samples not used in the cons truction of the models. The OSC-PLS model was able, with sufficient accurac y, to predict the hydroxyl content of several calcined silicas with differe nt physical properties. Copyright (C) 2000 John Wiley & Sons, Ltd.