Laser ablation at high repetition rate coupled to laser-induced breakdown spectroscopy for analysis of non-matrix matched standards

Laser ablation at kilohertz repetition rate coupled to laser-induced breakdown spectroscopy (kHz LA-LIBS) was used for the analysis of non-matrix matched metallic standards. Kilohertz LA-LIBS exploited the demonstrated advantages of the analytical technique referred to as laser-ablation laser-induced breakdown spectroscopy (LA-LIBS), while at the same time increased the amount of ablated mass available for analysis. By separating the laser ablation process from the excitation and analysis stages, every configuration of LA-LIBS has demonstrated to produce better analytical results during the analysis of non-matrix matched samples. This research reports the analytical response of five analytes (Al, Cu, Fe, Mg and Mn) from eight standard reference materials. The standards included four aluminum alloys, a high temperature alloy, a cupro‑nickel alloy, a stainless steel and a low alloy steel. The analytical performance of kHz LA-LIBS was evaluated through the estimation of the signal-to-noise ratio, relative standard deviation, linearity and y-intercept of calibration curves and limits of detection. Calibration plots relating the analyte concentration to the Fe-normalized (internal standard), peak-to-background and net intensities were constructed. The increased amount of ablated mass in kHz-LA-LIBS rendered superior figures compared with traditional LIBS and other LA-LIBS configurations. The limits of detection of kHz LA-LIBS were improved by 3 to 14 times as compared to those reported previously and were estimated in the range of 0.07 and 0.30% by mass.