Ether and ester moieties in Messel shale kerogen examined by hydrolysis/ruthenium tetroxide oxidation/hydrolysis

A degradation procedure that consists of an alkaline hydrolysis/ruthenium tetroxide oxidation/alkaline hydrolysis sequence was applied in order to differentiate ether and ester moieties in Messel shale kerogen. A substantially larger amount of mono- and dicarboxylic acids was isolated in post-oxidation hydrolysis, compared to the amount of acids isolated in the direct hydrolysis of the native kerogen, which is an indication of the predominance of ether over ester moieties in the structure of this kerogen. Most of the substituents on aromatic rings appear to be in the form of alkyl–aryl ethers. In order to obtain additional structural information, the observed degradation products were compared with the degradation products from alkaline permanganate oxidation of the same kerogen sample.