Effect of Optimum Parameters Setting on Laser-Induced Breakdown Spectroscopy

Abstract

Laser-induced breakdown spectroscopy is very attractive analytical method owing to many advantages, but it is complicated by the matrix effect due to complex nature of the laser–sample and plasma–particles interaction processes. For more precise and accurate analysis results, this effect must be reduced to a minimum. The approach used in this study to reduce the matrix effect was based on the selection of the optimum parameters of the system using pure element standards, followed by data processing and various normalization techniques. The copper alloys were selected for this study knowing that these materials are particularly difficult to be analyzed by laser-induced breakdown spectroscopy due to large differences in the physical properties of the metal constituents. But the accuracy improvements obtained by the proposed approach are encouraging to generalize it to other similar materials. Eighteen reference standards of copper alloys were measured to construct the calibration curves after optimum parameter settings. The coefficients of determination, R ², obtained from the calibration curves of most elements present in copper alloys were close to 1 (0.99). The validation of this approach was verified by extra reference standards measurement, which gives relative measurement errors varying from about 1–8% according to the inverse level of the element concentration.

Keywords:

• LIBS analysis
• normalization techniques
• optimum parameters
• reduction of matrix effect

Notes

*Out of the range of the calibration curve.

*OPS: Z46-200 mJ −1 µs, optimum parameters setting PS-01: Z44-200 mJ −1 µs; PS-02: Z44-200 mJ −2 µs; PS-03: Z46-300 mJ −1 µs.

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