Twenty heavy and/or particle-rich crude oils have been quantitatively fractionated into saturates, aromatics, resins, and asphaltenes (SARA) by asphaltene precipitation in n-hexane and highperformance liquid chromatography (HPLC). The newly developed and fully automated HPLC method has a sample capacity corresponding to 0.6 g of heavy crude oil. The crude oils have been characterized by vibrational spectroscopy in the near-infrared (NIR) and infrared (IR) regions. Principal component analyses (PCA) of the data sets from IR and NIR were performed so that exploratory data analyses could be conducted. Partial least-squares (PLS) regression models were built for each SARA component from IR and NIR data to predict the amounts of SARA components. These models successfully fitted the experimental data from NIR analyses and showed good predictive ability for the crude oil composition. The regression models from IR data were not modeled properly for aromatics and asphaltenes but were modeled excellently for saturate and resin components. For SARA determination, NIR spectroscopy appears to be a favorable alternative to the more time-consuming fractionation method.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.