Preliminary study of metalloporphyrins in some oil shales, red sea, Egypt

Abstract Occurence and distribution of metalloporphyrins were studied in asphaltene and maltene fractions of some Egyptian oil shales from the main producing mines (Abu-Shegeili, El-Beida, El-Nakheil and Abu-Tundub I, II) in red sea area (Fig. 1). Metalloporphyrins were extracted using adsorption column chromatography. The presence of Ni, Fe and Vo-porphyrins was monitored in each fraction by means of UV–Visible spectrometry, the result indicated that metalloporphyrins could be a mixture of Etio and DPEP types. Each fraction using UV–Visible spectrometry cannot differentiate between Ni and Fe porphyrins, so the extracted metalloporphyrins were subjected to purification and separation from each other by using thin layer chromatography (TLC). HPLC was used for fingerprinting Vo, Ni and Fe-porphyrins, it was found that the different porphyrins exhibited wide different chromatograms. HPLC technique could be used as a successful tool to characterize Fe and Ni-porphyrins.