DOI: 10.1063/1.4978841

Authors
Ali, J. ; Haider, Z. ; Imran, M. ; Sabri, S. ; Tariq, U. ; Tufail, K.

Keywords

Abstract

Laser-induced breakdown spectroscopy (LIBS) is a direct and versatile analytical technique that performs the elemental composition analysis based on optical emission produced by laser induced-plasma, with a little or no sample preparation. The performance of the LIBS technique relies on the choice of experimental conditions which must be thoroughly explored and optimized for each application. The main parameters affecting the LIBS performance are the laser energy, laser wavelength, pulse duration, gate delay, geometrical set-up of the focusing and collecting optics. In LIBS quantitative analysis, the gate delay and laser energy are very important parameters that have pronounced impact on the accuracy of the elemental composition information of the materials. The determination of calcium elements in the pelletized samples was investigated and served for the purpose of optimizing the gate delay and laser energy by studying and analyzing the results from emission intensities collected and signal to background ratio (S/B) for the specified wavelengths.

DOI: 10.1063/1.4978834

Authors
Ali, J. ; Haider, Z. ; Imran, M. ; Tufail, K.

Keywords

laser-induced plasma; plasma spectroscopy; zinc; manganese; gate delay; calibration curve; normalization;INDUCED BREAKDOWN SPECTROSCOPY; FORENSIC ANALYSIS; SELF-ABSORPTION; EMISSION; LIBS; SPECTROMETRY; ABLATION; INKS

Abstract

Laser-induced plasma spectroscopy is performed to determine the elemental compositions of manganese and zinc in potassium bromide (KBr) matrix. This work has utilized Q-switched Nd: YAG laser installed in LIBS2500plus system at fundamental wavelength. The pelletized sample were ablated in air with maximum laser energy of 650 mJ for different gate delays ranging from 0-18 mu s. The spectra of samples are obtained for five different compositions containing preferred spectral lines. The intensity of spectral line is observed at its maximum at a gate-delay 0.83 mu s and subsequently decayed exponentially with the increasing of gate delay. Maximum signal-to-background ratio of Mn and Zn were found at gate delays of 7.92 and 7.50 mu s, respectively. Initial calibration curves show bad data fitting, whereas the locally normalized intensity for both spectral lines shows enhancement since it is more linearly regressed. This study will give a better understanding in studying the plasma emission and the spectra analysis.