DETERMINATION OF MOLECULAR MASSES FOR PETROLEUM DISTILLATES BY SIMULATED DISTILLATION

Determination of Molecular Mass (MM) for petroleum distillates is explored for selected samples via High Temperature Simulated Distillation (HTSD). MM is determined as a by-product from routine HTSD carried out using open wall capillary columns coated with apolar stationary phases. No sample pre-separation into hydrocarbon group-types is required. Determined MM values were validated with results achieved via correlations based on specific gravity and refractive index. Furthermore, determined MM with the former methodologies were found to match mass spectrometric determinations carried out for the basic polar components present within the studied samples. Moreover, HTSD analyzed petroleum distillates are proposed as more representative calibration standards for size exclusion chromatographic separations, thus opening the feasibility of extrapolating MM determination for non volatile petroleum residua.