Validation of reducing-difference procedure for the interpretation of non-polarized infrared spectra of n-component solid mixtures.

Validation of reducing-difference procedure based on subtracting of non-polarized infrared (IR) spectra of n-component solid mixtures is presented. The accuracy and precision are established. The limits of detection are 3.0, 2.5, 1.5 and 1.0wt.% for 5-, 4-, 3-and 2-component mixtures, respectively. Smoothing procedures for IR spectral analysis, based on Savitzky-Golay or Fourier methods are applied as well. The mean values and relative standard deviations for peak position (nu(i)) and integral absorbance (A(i)) obtained by this data processing approach have been examined using Student's t-test.