Optimization of the LIBS Parameters for Detection of Trace Metals in Petroleum Products

Abstract

Parametric dependence of laser-induced breakdown spectroscopy (LIBS) for detection of trace elements has been studied. LIBS was applied for quantitative measurements of environmentally important trace metals such as magnesium, lead, copper, and calcium in oil samples. This work incorporates investigations of LIBS experimental parameters such as the distance between the plasma and optical fiber, sample rotation speed, laser pulse energy, gate delay, and position of the focal spot on the pellets. The optimized parameters are tested for the preparation of the calibration curves for Mg, Pb, Cu, and Ca. Limits of detection (LOD) of our LIBS system were also estimated for these elements. The system was applied for trace metals detection in Arabian crude oil residue samples which is not trivial to detect with conventional techniques.

Keywords:

• analysis of solid crude oil waste
• continuous emissions monitoring
• environmental impacts of trace metals
• laser-induced breakdown spectroscopy (LIBS)
• LIBS applications
• LIBS for powder samples
• trace metals detection

Acknowledgments

The support by the Physics Departments and King Fahd University of Petroleum and Minerals is gratefully acknowledged. One of the author (T.H.) is thankful to the National University of Science and Technology and Government of Pakistan for finacial support for his Ph.D. work. He is also thankful to KFUPM for its hospitality and permission to work at its research facilities. The authors are thankful to Dr. Chandana Senaratne for ICP analysis.

Notes

^a Source: Striganov and Sventitski (1968).