Canadian Journal of Pure & Applied Sciences

Abstract: A comparative study of toxic speciation in crude oil and asphaltenes has not been previously reported and contributes to knowledge in fuels research. Crude oil is used on land farms; and asphaltenes are converted to asphalt for constructing roads. Toxic components in these substances could, therefore, pose a distinct threat to the environment. In this study, asphaltene fractions were isolated from crude oil samples via soxhlet extraction. The native crude oil and abstracted asphaltenes were then subjected to investigation for toxicity using an ultra-sensitive hyphenated facility. A Perkin Elmer SCIEX DRC-e ICP-MS was coupled with a liquid chromatographic system (HPLC) for simultaneous detection and convenient resolution of all four species. Stationary and mobile phases were prepared according to standard protocol. The elution rate was 1.2 mL/min; and corresponding retention times (min) were: As3+: 1.61; As5+: 4.06; Cr3+: 3.71; and Cr6+: 5.80. The system possesses a built-in dynamic reaction cell (DRC) to enhance mass detection. The oxygen flow in the DRC was controlled to give a rate of ~0.4 mL/min. Following mass detection, m/z values of 52 characterized the Cr3+/ Cr6+ species; while the arsenic components were detected as adduct ions, AsO+, m/z, 91, after coalescing with oxygen. The levels of the species of interest were compared for crude oil and asphaltenes and the data revealed a preponderance of the detected species in the asphaltene phase. The feasibility of applying the experimental data in “fingerprinting” studies was examined; and the impact of our study in terms of environmental protection and sustainable development is discussed