Determination of the Weight Percent of Aromatic Compounds in a Heavy Fuel Oil by Using Flash Chromatography and Solid-phase Extraction Coupled With High-Temperature Two-Dimensional Gas Chromatography and Electron Ionization Time-of-Flight High-Resolution Mass Spectrometry.

A chromatography/mass spectrometry method is presented for the determination of the weight percent of aromatic compounds in a heavy marine fuel oil. This information facilitates the estimation of the stability, engine performance, and environmental as well as health-related consequences related to heavy fuel oils. These fuel oils are complex mixtures of many different compound types. Thus, a previously reported method was used to first separate the oil sample via distillation, precipitation, and fractionation into asphaltenes, heavy saturated hydrocarbons, alkylaromatic hydrocarbons, aromatic and heteroaromatic, as well as polar compounds. For the fractionation, both flash column chromatography and solid-phase extraction techniques were utilized to ensure proper separation of the compound classes in the maltenes fraction of the sample. High-temperature two-dimensional gas chromatography coupled with high-resolution electron ionization time-of-flight mass spectrometry was used to determine the overall compound compositions of the obtained fractions (other than the asphaltenes) and to classify the detected compounds. The results indicate that the saturated compound fraction contained only alkanes, while all the other fractions contained aromatic compounds. Combining the weight percent of these fractions was used to determine the weight percent of the aromatic compounds in the oil sample.