Rapid and direct characterization of total fatty acids in wood by thermochemolysis-gas chromatography-flame ionization detector/mass spectrometry with tetrabutylammonium hydroxide

Conventional methods used to analyze total fatty acids in wood generally require tedious and time-consuming pretreatments such as solvent extraction and hydrolysis of esterified fatty acids of fats. In this study, both total fatty acid composition and the yield from free and esterified fatty acids of fats in Acacia species were investigated using a rapid and direct method of thermochemolysis-gas chromatography (GC)-flame ionization detector (FID)/mass spectrometry (MS) with organic alkalis. Using tetrabutylammonium hydroxide (TBAH) at 300 °C, thermochemolysis-GC-FID/MS gave total fatty acids including the fat origin as pyrolyzates with suppressed lignin fragment formation because of the basicity of TBAH compared to other organic alkalis: tetramethylammonium hydroxide and tetramethylammonium acetate. The obtained results of fatty acid composition were consistent with those obtained using conventional methods consisting of a series of procedures such as solvent extraction, hydrolysis, derivatization, and analysis by GC-FID/MS in fatty acid composition analysis. Furthermore, thermochemolysis-GC-FID gave a higher yield of total fatty acid than the conventional method, quantitatively reflecting the difficulty in solvent extraction of these components. Consequently, thermochemolysis-GC with TBAH promises to be a rapid and direct method to characterize total fatty acids in wood, avoiding artifacts by solvent extraction of wood. Furthermore, this method discriminated Acacia auriculiformis from Acacia mangium based on the observed fatty acid contents and selected individuals containing low total fatty acids to minimize paper sliding on a printer drum.