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Thermally assisted hydrolysis and methylation-gas chromatography (THM-GC) using a vertical microfurnace pyrolyzer and a flame ionization detector (FID) was applied to rapid analysis of chemical composition for polyunsaturated fatty acid (PUFA) components in human serum. Here, the authors used a reactive thermal desorption (RTD) method, where 2 μL of a serum sample was subjected to the THM reaction at 250 °C for 20 s, to detect PUFA components with high selectivity and sensitivity. The resulting chromatograms clearly showed a series of fatty acid methyl esters including PUFAs without any interference peaks derived from the matrix components of the serum samples. Furthermore, the observed chemical composition and n-6 / n-3 ratio for PUFA components were in good agreement with those obtained by a conventional analytical technique involving solvent extraction and transmethylation. • Reactive thermal desorption (RTD) enabled selective detection of PUFAs. • N-6 / n-3 PUFA ratios were analyzed rapidly and conveniently. • Only 2 μL of a human serum sample was enough to be analyzed. • Tedious and time-consuming sample pretreatments were not required. [ABSTRACT FROM AUTHOR]

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]