Identification of substances by THz spectroscopy and multivariate analysis

The identification of different substances based on terahertz transmittance spectra and multivariate analysis (MVA) is demonstrated. Transmittance spectra are obtained by the use of a Fourier transform infrared spectrometer (FTIR). By means of principal component analysis (PCA) and partial least squares regression (PLS) the spectral data were analyzed in order to discriminate and to identify the substances from each other.