Investigation of resonance-enhanced laser-induced breakdown spectroscopy for analysis of aluminium alloys

Abstract

Resonance-enhanced laser-induced breakdown spectroscopy (RELIBS) was investigated with the aim to improve the limit of detection of trace elements in the context of elemental analysis of aluminium alloys. A Q-switched Nd:YAG laser pulse (7 ns, 1064 nm) was used for ablation of the samples and was followed, after a suitable delay, by an Optical Parametric Oscillator (OPO) laser pulse (7 ns), tuned at 396.15 nm, to resonantly excite the aluminium host atoms. In particular, the Mg I 285.21 nm and Si I 288.16 nm lines were observed in the acquisition spectral window. We investigated the influence of the main experimental parameters, namely, the excitation wavelength, the interpulse delay and the ablation and excitation fluences, on the signal-to-noise ratio for the Mg I 285.21 nm line. We found that, at low ablation fluences, typically less than a few J cm À2 , the Mg signal at 285.21 nm achieved using RELIBS was significantly enhanced when compared to LIBS using the same ablation fluence. At fluences higher than 8 J cm À2 , the effect of the excitation pulse became unnoticeable and similar results were observed for both approaches. The optimum conditions were achieved for an interpulse delay of about 30 ns, an ablation fluence of about 3.8 J cm À2 and an excitation fluence of about 1.1 J cm À2 . The corresponding absolute LoDs were 0.7 and 50 fg, for Mg and Si, respectively, using RELIBS. When using LIBS, they were 4 and 128 fg, instead. Finally, the applicability of RELIBS in the context of a minimally destructive elemental analysis is discussed.

Improving the Detection Sensitivity for Laser-Induced Breakdown Spectroscopy: A Review

“…The spectral intensity achieved using resonant DP-LIBS is approximately 1-2 orders of magnitude higher than that with signal pulse LIBS. In one study, the resonant DP-method was used to analyze aluminum alloy and decrease the LODs of Mg and Si to 0.7 and 50 fg, respectively [54]. This method has also been used to detect TiO 2 aerosols, achieving a signal enhancement of 220 times [55].…”

Improved Analysis of Manganese in Steel Samples Using Collinear Long–Short Double Pulse Laser-Induced Breakdown Spectroscopy (LIBS)

“…One vital subject among these studies is the analytical performance of LIBS for the industrial application. To improve the performance, many approaches have been developed based on LIBS, such as microwave-assisted LIBS, 22,23 LIBS laser-induced fluorescence (LIF), 24 resonance-enhanced LIBS, 25,26 double-pulse LIBS (DP-LIBS), 27–33 etc. However, it is still difficult to apply LIBS to the steelmaking process because of the terrible measurement conditions in steel plant.…”

Quantitative Determination of Cd in Soil Using Laser-Induced Breakdown Spectroscopy in Air and Ar Conditions

“…However, the high detection limit of elements has always been a difficult problem to restrict the application of LIBS [ 18 ]. Therefore, LIBS signal enhancement technologies have become the focus of scholars at home and abroad, mainly including double pulse LIBS [ 19 , 20 , 21 ], nanoparticle enhanced LIBS [ 22 , 23 ], spatial-confinement LIBS [ 24 , 25 ], resonance-enhanced LIBS [ 26 , 27 ], and so on. Besides, the signal enhancement technique based on argon (Ar) is also one of the most promising techniques for signal enhancement.…”