Laser ablation—laser induced breakdown spectroscopy (LA-LIBS): A means for overcoming matrix effects leading to improved analyte response

Abstract

Laser-ablation laser-induced breakdown spectroscopy (LA-LIBS) is proposed as a novel analytical scheme with goals of improved analyte response, minimization of sample matrix effects, and use of non-matrix matched standards. A direct comparison of the LA-LIBS approach and a traditional direct LIBS analysis was made for a set of seven reference materials, ranging from nearly pure iron to copper-nickel and aluminum alloys. The precision of each approach was assessed using calibration curves, and the LA-LIBS configuration was demonstrated to consistently produce a superior analytical response, as assessed by the linear least-squares fit correlation coefficient and y-intercept values. Significantly, the normalized (by Fe) response of the four targeted analyte species (Al, Mn, Mg and Cu) was successfully reduced to a single calibration curve with the LA-LIBS approach. In addition, particle size measurements of the laser-ablation plume were recorded along with SEM and white-light interferometry analysis of ablation craters for assessment of the analytical sample as presented to the analytical LIBS plasma. Finally, the effect of carrier gas is explored by substitution of nitrogen with helium.