Effect of surface topography in the characterization of stainless steel using laser-induced breakdown spectrometry

A pulsed Nd:YAG laser operating on the second harmonic wavelength at 532 nm was used in this work, The influence of sample surface topography on spect ral emission of laser-produced plasmas was investigated, Stainless-steel sa mples,vith different grades of surface polishing (range 0.026-4.54 mu m) we re prepared and analysed using LIES. The effect of surface roughness on ana lytical precision was found to be dependent on laser beam energy, with opti mum results for beam irradiances in the range 28-57 GW cm(-2). The reproduc ibility of spectral emission for pre-ablated surfaces also has been investi gated. Limits of detection of molybdenum in stainless steel at different sa mple finishes and for several laser irradiances are discussed, Copyright (C ) 1999 John Wiley & Sons, Ltd.