Non-matrix matched calibration using near-IR femtosecond laser ablation inductively coupled plasma optical emission spectrometry

The facilities of near-IR (NIR) femtosecond laser ablation (fs LA) inductively-coupled plasma optical emission spectrometry (ICP-OES) for the analysis of solid materials applying non-matrix matched standards have been examined. Three sets of metallic and dielectric standards ( brass, aluminium, silicate glass) have been analyzed for Zn and Cu using He as buffer gas. It has been found that the measured Zn/Cu ratio of these standards remains nearly unchanged in the fluence range considered (0.8 J cm(-2) <= F <= 11.0 J cm(-2)). At fluences close to the threshold, however, the Zn/Cu ratio for brass and aluminium tends to slightly increase, suggesting preferential evaporation of Zn during the ablation process. Furthermore, LA above a fluence of 5 J cm(-2) resulted in linear, matrix-independent calibration graphs. According to the results achieved, NIR fs LA-ICP-OES carried out in the medium and high fluence regime permits efficient suppression of fractionation and performance of accurate analyses even if non-matrix matched standard materials have to be used.