Identifying Type of Refined Petroleum Products in Environmental Media: Thin-Layer Chromatography (TLC) as a Quick Methodology

Abstract

The ultimate goal of our study is to establish thin-layer chromatography (TLC) as a quick and simple method for identifying the type of refined petroleum products present in the environmental media. As a pre- liminary step, TLC chromatograms of different petro- leum products, including gasoline, kerosene, and diesel, were characterized and compared. Methanol was deter- mined as the optimum carrier solution in TLC analysis. The spherical-shaped TLC chromatogram of gasoline showed the longest migration distance, and thus the highest retardation factor (Rf )o f 0.91. This was follow- ed by that of kerosene (0.63) with an elliptical-shaped, and diesel (0.24) with an elongated trapezoid-shaped chromatogram. Rf of kerosene and diesel increased with the dilution factor, while gasoline showed a constant value. Additionally, it was observed that the TLC chro- matograms of oils produced the same peak pattern with the corresponding petroleum products in gas chroma- tography (GC). A mixed sample of kerosene and diesel presented a triangular shaped chromatogram, underlining the need to consider the shape of chromato- gram in addition to the Rf value, as an indicator of the petroleum type. The findings indicate that TLC has a huge potential to be used as a quick and reliable method for identifying the type of refined petroleum products in the environmental media.