Rapid characterization of wood extractives in wood by thermal desorption-gas chromatography in the presence of tetramethylammonium acetate

A novel rapid and sensitive method to characterize wood extractives in wood samples was developed on the basis of reactive thermal desorption-gas chromatography (RTD-GC) in the presence of an organic alkali, tetramethylammonium acetate ((CH₃)₄N⁺OCOCH₃ ^-, TMAAc) without using any cumbersome pretreatment such as solvent extraction. The RTD at 200°C using TMAAc allowed highly sensitive detection of wood extractives such as fatty acid, phenolic acid and gallocatechin components in Eucalyptus camaldulensis as their methyl derivatives on the resulting chromatograms with suppressing the pyrolysis of the major wood constituent to the utmost. The fatty acid contents were able to be determined directly by RTD-GC using approximately 100 μg of the powdered wood samples with in relative standard deviations of 5%. The observed result was in fairly good agreement with that obtained by the conventional standard method including off-line transmethylation of acetone extracts followed by GC measurements.