Analysis of aliphatic biopolymers using thermochemolysis with tetramethylammonium hydroxide (TMAH) and gas chromatography–mass spectrometry

Selected aliphatic biopolyesters (cutins, cuticles and a suberin) isolated from different plants have been analyzed using thermochemolysis with tetramethylammonium hydroxide (TMAH). This method consists of a high-temperature saponification/transesterification, and yields methyl esters of fatty acids and the methyl ethers of alcohols, which are subsequently analyzed by gas chromatography and gas chromatography–mass spectrometry. The main compounds produced from the analyzed samples correspond to the methyl derivatives of long-chain fatty acids, hydroxy fatty acids and α,ω-alkanedioic acids. The composition of the released compounds are similar to those reported in the literature using different depolymerization methods. The main advantage of the procedure is that it is easily performed in glass tubes with very low amounts of sample and without additional derivatization steps prior to gas chromatographic analysis because the products are methylated in situ. The method also avoids the laborious and time consuming sample preparation of extractive methods and the use of large amounts of solvents.