RAPID CHARACTERIZATION OF WOOD PULP LIGNIN BY FOURIER-TRANSFORM RAMAN-SPECTROSCOPY

FT-Raman spectroscopy is used for the rapid measurement of wood pulp l ignin. A total of 23 western softwood pulp samples with known kappa nu mbers (10-38) are used. Each sample is divided into three portions and scanned separately. The integrated area of the lignin band at approxi mately 1600 cm(-1) is ratioed against the integrated area of the cellu lose bands in the 1200-1010 cm(-1) region and correlated to known kapp a numbers. The measured ratios behave linearly with the kappa number ( r = 0.99) and can be reproducibly determined with an error of approxim ately 2% or less. The data are presented and discussed in view of the potential for at-line analysis of lignin associated with chemical deli gnification of wood pulp. (C) 1997 Academic Press.