Chemometric Unmixing of Petroleum Mixtures by Negative Ion ESI FT-ICR MS Analysis

Identification and quantification of mixed sources of petroleum reservoirs as well as the sources of oil spills generally requires the molecular composition information about the mixture. In this study, the relative concentrations of a series of polar acidic compounds, semiquantified by negative ion ESI FT-ICR MS, were calculated using alternating least-squares (ALS) to unmix a group of oil mixtures prepared in the laboratory using three endmember oils. It was shown that the ALS results were accurate based on the relative concentrations of polar acidic compounds, regardless of whether endmember oils and several samples were removed from the sample set. ALS was able to accurately calculate the composition of endmember oils, regardless of whether they were included in the sample set. This method is relatively simple, efficient, time-saving, and has potential for geological source identification of mixed oils or oil spills.