Systematic characterisation of long-chain aliphatic esters of wool wax by gas chromatography–electron impact ionisation mass spectrometry

A detailed structural characterisation of the aliphatic high-molecular-mass esters extracted from raw wool based on high-temperature gas chromatography–electron impact ionisation mass spectrometry is described. The raw wool esters extracted are in the range of C37 to C54 (i.e., molecular mass 550–788). The selected ion chromatogram exhibited four isomers for the esters with an odd number of carbon atoms (i:a, i:n, a:n and n:n) and five for those with an even number of carbon atoms (i:i, a:a, i:n, a:n and n:n). Isomeric structural elucidation is discussed with respect to the long-chain fatty acid and long-chain fatty alcohol structures, on the basis of chromatographic retention behaviour and mass spectral information.