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Abstract: Thermochemolysis-gas chromatography in the presence of tetrabutylammonium hydroxide was applied to the direct determination of phenolic compounds present as “extractives” in a wood sample (Eucalyptus camaldulensis). The phenolic extractives converted into their perbutyl derivatives were separated from the other phenolic products derived from the lignin skeleton in the observed chromatogram of the wood sample. On the basis of their peak intensities, the contents of the phenolic extractives in the wood sample were rapidly and precisely determined without using preliminary solvent extraction of the wood sample. [Copyright &y& Elsevier]

Highlights • THM-GC was applied to monitor the change in copolymer composition of film samples during soil burial test. • 3 HHx moieties in the polymer chains were preferentially biodegraded owing to their low crystallinity. • Local variation in the degree of biodegradation using only 30 μg of P(3HB-co-3HHx) film sample. Abstract Soil burial biodegradation behavior of poly(3-hydroxybutyrate- co -3-hydroxyhexanoate) [P(3HB- co -3HHx)] was studied based on its copolymer composition determined by thermally assisted hydrolysis and methylation-gas chromatography (THM-GC). The change in copolymer composition of P(3HB- co -3HHx) film samples during soil burial degradation test was monitored in detail by THM-GC. As a result, the copolymer compositions of 3HB units gradually increased, while those of 3HHx units decreased with soil burial time, almost correlating with recovery weight. Based on these results, the biodegradation mechanism of P(3HB- co -3HHx) was elucidated with considering the influence of the crystallinity on the biodegradability. Furthermore, local differences in biodegradability of a given P(3HB- co -3HHx) film after soil burial test were also successfully evaluated from the copolymer compositions obtained by THM-GC. [ABSTRACT FROM AUTHOR]

Abstract: 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. [Copyright &y& Elsevier]

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. [Copyright &y& Elsevier]