Characterization of diffuse reflectance fiber probe sampling on moving solids using a Fourier transform near-infrared spectrometer

A characterization of the effect of sample movement on spectral response us ing an FT-NIR spectrometer is presented. The data were evaluated by means o f both multivariate data analysis and visual inspection of interferograms a nd spectra. A fiber-optic probe was used to collect spectra from model samp les such as paper, plastic and fine and coarse powders. During controlled m ovement at velocities between 0.046 and 0.73 m s(-1), it was found that sam ple movement causes features not normally present in the interferograms. Ho wever, it is shown that after transformation to frequency domain single-bea m spectra these artifacts are present well outside the near infrared spectr al range (10,000-4000 cm(-1)). The implication of these results is that FT- NIR is a suitable technique for process analysis of samples moving with low or moderate velocities. (C) 2001 Elsevier Science B.V. All rights reserved .