Polycyclic aromatic hydrocarbons in crude oil-contaminated soil: A two-step method for the isolation and characterization of PAHs.

A two-step analytical method is developed for the isolation and characterization of polycyclic aromatic hydrocarbons (PAHs) in crude oil contaminated soil. In the first step, those crude oil components were isolated which are easily mobilized with water from the contaminated soil (determination of groundwater pollution potential). In the second step, the fraction containing the remaining crude oil compounds was extracted using toluene. After the cleanup of the fractions, both fractions were analyzed using high-performance liquid chromatography (HPLC). The HPLC of the toluene extracted fraction shows that along with the sixteen priority pollutants from the US-EPA list, many other polycyclic aromatic hydrocarbons (PAHs) are present as well. It is evident from the chromatograms that a significant amount of PAHs are present as is also the case in the fractions eluted by water. The described method allows the determination of total organic pollutants from crude oil, some of them being potential groundwater contaminants. The major part of the total pollutants could not be mobilized by water and therefore remains in the soil, which was extracted in the second step.