الفهرس 
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Abstract
Occurrence and distribution of metalloporphyrins were studied in asphaltene and maltene fractions of some Egyptian oil shales, which were assembled from the main producing mines (Abu-Shegeili, El-Beida, El-Nakheil and Abu-Tundub) in Red Sea area. Metalloporphyrins were extracted using adsorption column chromatography. The silica gel column exhibits brown, dark red, red and pink colored zones. The brownish zone is due to the resin materials, which accompanied with asphaltene, the zones of dark red and red colors are due to vanadyl porphyrins and the zone of pink color may reflect the separation of iron porphyrins. The presence of nickel, iron, and vanadyl porphyrins was monitored in each fraction by means of UV-visible spectrometry. Furthermore, the extracted metalloporphyrins were subjected to purification and separation of the chelating porphyrins from each other by means of thin layer chromatography (TLC). UV-visible results indicated that metalloporphyrins could be a mixture of Etio and DPEP types. UV-visible spectrometry can not differentiate between Ni porphyrins and Fe porphyrins. HPLC was used for fingerprinting VO, Ni and Fe porphyrins. It was found that VO, Ni and Fe porphyrins exhibited the wide different chromatograms. Therefore, HPLC technique could be used as a successful tool to characterize Fe porphyrins from Ni chelating complexes. Samples of metalloporphyrins (VO, Ni, and Fe) were subjected to mass spectrometry in order to elucidate the structure of different types of porphyrins. The mass spectra appeared as truncated series of mass numbers which is characteristics of geo-porphyrins in sediments or oil shales. The data indicated that the five types of porphyrins (Etio, DPEP, BEtio, BDPEP, and THBD) with carbon numbers ranging from C20 to C50 were present in considerable detection level. Each type exhibits several maxima of carbon numbers. Based on mass spectrometric data, the major components of metalloporphyrins (VO, Ni or Fe), present in the organic constituents of the studied oil shale, were identified and their chemical structures were suggested. Occurrence and distribution of VO, Ni, and Fe porphyrins were interpreted from geochemical point of view. This was achieved based on the available data about the studied oil shales, particularly, maturation levels and oil-gas potentials of the deposited organic matters