Mapping of Basic Elements of Crude Oil Samples Collected from Different Oilfields in Sudan by using Laser Induced Breakdown Spectroscopy Technique

Abstract

This research aim to use modern scientific technique which is laser induced breakdown spectroscopy to identify the components of some crude oil samples. This technique was selected in this work due to its unique characteristics in terms of ease, speed and no sample preparation. Three samples of crude oil were used in this work, collected from different locations in Sudan: Rawat, (White Nile), Melut (Upper Nile- Jonglei) and Hadida (East Darfur). These samples was irradiated by Nd:Yag laser at 1064 nm , pulse duration10 ns , RR2Hz, with pulse energies of 120,150,170 and 190 mJ. The result was analyzed by using atomic spectra data base (ASD) from national institute of standard and technology (NIST) and showed considerable amount of the main elements in crude oil (C, H, N, O and S) in all three samples with different ionization stages due to the different in laser energy pulse. Also transition metals such as Fe, Ti, Sc, V, Co, Mn, Ni, Cr, Cu and Mo. Earth metals like Al, Th and B also were appeared. In addition to heavy elements like Hg, Cd was finding. Also the spectra of the samples showed light elements such as He, Li, gaseous elements like Ar, Ne, Cl in addition to Alkali elements Ca, Na, Cs, K, Ba and Mg. The spectra due to trace elements such as Zn, Si, P,U, Gawere recorded using this technique. The obtained results showed that the crude oil samples has many elements and varies from one field to another in relation to the change in the age, depth and location of the well. This work illustrated that LIBS technique was useful when apply to liquid sample and for hazard (flammable) samples like crude oil with reasonable detection limit and no sample preparation.