APPLICATION OF DIFFUSE-REFLECTANCE INFRARED FOURIER-TRANSFORM SPECTROSCOPY TO THE QUANTITATIVE-DETERMINATION OF ACETYL GROUPS IN WOOD

The quantitative determination of acetyl groups in milled cottonwood t reated with alkali by IR spectroscopy is presented. The diffuse reflec tance infrared Fourier transform (DRIFT) spectroscopy quantification i s based on the variation of the peak height at 1735 cm(-1) due to the hemicellulose carbonyl groups, which is then normalised to the 1510cm( -1) band assigned to lignin aromatic ring vibration as the internal st andard. A good correlation with values obtained by gas chromatography is reported. Applied on milled wood samples the DRIFT procedure is rap id and direct, requires no preparation and is non-destructive, This st udy demonstrates that the acetyl content of wood can be conveniently d etermined by DRIFT spectroscopy.