Mass spectrometric analysis of acids obtained by oxidation of diesel fuel cut

Processes have been developed for obtaining petroleum acids by partial oxidation of a diesel fuel cut by atmospheric oxygen in the presence of a catalytic system at 413-423K. The presence of the carboxyl group COOH is confirmed by the IR spectrum as shown. For mass spectrometric analysis, the petroleum acids were converted to the less polar and more volatile silyl esters. Molecular mass distribution curves are presented and the group composition of the acids is given. In the oxidation of the diesel fuel cut, naphthenic and aromatic acids are formed along with the aliphatic acids.