Removal of Air Interference in Laser-induced Breakdown Spectrometry Monitored by Spatially and Temporally Resolved Charge-coupled Device Measurements

Abstract

Laser-induced breakdown spectrometry is a suitable method for the direct in-process measurement of materials composition. The emission spectrum from the plasma includes information not only on the analysis area but also on the surrounding atmosphere, mainly lines corresponding to O, N and C if the experiments are being carried out in air at atmospheric pressure. These emission lines could interfere with the sample spectrum. Although working under vacuum conditions or the use of controlled atmospheres can be considered to be the best choice, in most practical applications working in air at atmospheric pressure is the common way of analysis. A study was undertaken to evaluate the removal of air interferences in poly(methyl methacrylate) samples by using the temporal and spatial resolution of gated charge-coupled devices, without any sample treatment or alteration of the experimental set-up.