Application of diffuse reflectance infrared Fourier transform spectroscopy to the quantitative determination of acetyl groups in wood

Abstract

The quantitative determination of acetyl groups in milled cottonwood treated with alkali by IR spectroscopy is presented. The diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy quantification is based on the variation of the peak height at 1735cm-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 standard. A good correlation with values obtained by gas chromatography is reported. Applied on milled wood samples the DRIFT procedure is rapid and direct, requires no preparation and is non-destructive. This study demonstrates that the acetyl content of wood can be conveniently determined by DRIFT spectroscopy.