Wavelength dependant ablation rates for metals and silicate glasses using homogenized laser beam profiles - implications for LA-ICP-MS

Laser ablation (LA) inductively coupled plasma mass spectrometry (ICP-MS) i s a versatile micro-analytical technique for the determination of major, mi nor and trace elements in solid materials. Recent interest has concentrated on using the technique for layer analysis or depth profiling. However, lit tle data has been published on the rates of ablation which provide essentia l information for determining depth resolution. Knowledge of the ablation r ates is essential for the selection of optimum laser parameters for differe nt target materials. It also provides estimates of uncertainties for quanti fication on materials where no internal standard is available to correct fo r differences in ablation volume. This work presents results on the ablatio n rates of metals (such as Al, Cu, Ni, Ti, Mo, Pt, Zn, Cr and Si), the SRM NIST 600 series glasses and natural calcium fluoride for laser fluencies be tween 3.5 and 35 J/cm(2) using argon or helium as ablation environment toge ther with two fundamentally different types of lasers (193 nm Excimer and 2 66 mn Nd:YAG). (C) 2001 Elsevier Science B.V. All rights reserved.