Ashraf Yehia El-Naggar

Mass Spectrometry of Metalloporphyrins in Egyptian Oil Shales from Red Sea Area

Abstract Metalloporphyrins, extracted from asphaltene and maltene fractions of some Egyptian oil shales (Abu-Shegeili, El-Beida, El-Nakheil, and Abu-Tundub in the Red Sea area) by means of adsorption column chromatography and TLC, were subjected to mass spectrometry in order to elucidate the structure of different types of VO, Ni, or Fe porphyrins. Metalloporphyrins were not detected in maltene or asphaltene fractions of Abu-Shegeili oil shale. The mass spectra appeared as a truncated series of mass numbers, which is characteristic 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 levels. Based on mass spectrometric data, the major components of metalloporphyrins (VO, Ni, or Fe) were identified and their chemical structures were suggested. The occurrence and distribution of VO, Ni, and Fe porphyrins were interpreted from a geochemical point of view, particularly maturation levels and oil-gas potentials of kerogens.

Source input and maturation assessments of oil families depending on specific and gross geochemical aspects of crude oils from Bakr oilfields in the central Gulf of Suez, Egypt

ABSTRACT Different analytical techniques, including API gravity; sulfur–nickel–vanadium contents; liquid chromatographic separation; and gas chromatography, were utilized to investigate oil families of three crude oils collected from Bakr oilfield of middle-lower Miocene age and characterized by limestone facies at various depth locations in the central Gulf of Suez. These geochemical aspects were used to assess source input and maturation of oil families. The results showed that the studied oils indicate a close genetic relationship between studied crude oils, and classified as aromatic intermediate oils. These types of oils are characterized by mature sources derived mainly from marine inputs such as biomass from algae and plankton from different saline environments.

Quality Assessment of Honey Using Modern Analytical Tools

The quality of eighteen honey samples collected from the Western district of Saudi Arabia was assessed according to the International Honey regulatory standards using modern analytical methods. A number of quality criteria were measured to determine the botanical and geographical origin of honey. Hydroxymethylfurfural (HMF) as an adulteration marker was analyzed and detected quantitatively via high performance liquid chromatography (HPLC). The moisture content was assessed by Karl Fisher coulometric method using an automatic potentiometric titrator. While, mineral content and toxic heavy metal ions were determined using an inductively coupled plasma-atomic emission spectrometry (ICP-AES) technique after microwave digestion. All the investigated honey samples were of good quality. The elements with the highest frequency were K, Se, and Cd. High content of Cd and Se were found in samples (7 and 9). The maximum residues limit of the most dangerous metal for the human health lead was below European Standards.

Response surface methodology for carbon dioxide reforming of natural gas

ABSTRACT The performance of 0.5% wt Rh/γ-AL2O3 catalyst for the dry reforming of natural gas using carbon dioxide has been studied. The response surface methodology (RSM) is used to study the effect of two different operating parameters, namely the hourly space velocity at the levels 18,000, 36,000, 45,000, and 60,000 ccg−1 h−1 and the reaction temperature at the levels 600, 700, and 800°C, on the conversion of the different components comprising commercial natural gas. The RSM is used to illustrate such effect in the three dimensions and shows the location of the optimum for the conversion or production of each component.

Occurrences and distributions of normal alkanes and biological markers to detections of origin, environments, and maturation of crude oils in El Hamed oilfield, Gulf of Suez, Egypt

ABSTRACT The gas chromatography (GC) and gas chromatography–mass spectrometry (GC-MS) analyses for crude oils from Kareem reservoir in the wells El Hamed-1, 3, and 5 are used to provide information on source organic matters input, depositional environment, and maturation level. Data include normal alkane and acyclic isoprenoids distribution, terpane, and sterane aliphatic biomarkers. Pristine/phytane (Pr/Ph), Pr/nC17, and Ph/nC18 ratios indicated mixed organic sources of organic matters (kerogen type II, III) dominantly (kerogen type III) with a less effect of biodegradation and mature stage of occurrence. The diasteranes/steranes ratio showed generally low ratios as in most marine carbonate sources, while algal-bacterial organic matter contribution for the oil samples suggested dependence on the predominance of C23 tricyclic terpane relative to the C19 tricyclic terpane, and the C25 tricyclic terpane greater than C24 tricyclic terpane. The gammacerane index indicated that a low-salinity environment of deposition for the initial organic matters existed in the analyzed samples.