[Development and application of two-dimensional liquid chromatography for the analysis of polycyclic aromatic sulfur heterocycles in heavy oil].

A two-dimensional liquid chromatographic (2D LC) system was developed for the analysis of polycyclic aromatic sulfur heterocycles (PASHs) in heavy oil. The first dimension is a ligand-exchange chromatographic column packed with a palladium chloride/silica (PdCl-SiO) stationary phase, while the second dimension is a Spherisorb-NH column. The PASHs in vacuum gas oil were enriched online, and polycyclic aromatics hydrocarbons (PAHs) were separated according to their aromatic ring numbers. These separated fractions were analyzed by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), and detailed molecular characterization of PASHs and PAHs was achieved. Typical molecular structures of PASHs and PAHs in these fractions could be provided, and the side chain as well as the core structures were predicted. It is significant for the feedstocks selection and optimization of the hydrodesulfurization process by using these molecular characterization information.