LIBS analysis for on atmospherics pollutions of industrial sources
Abstract
In the frame of the air quality improvement, gas and particles emissions coming from incinerators are going to be more and more controlled. In order to promote the development of suitable analytical techniques, the French agency ADEME1 supports this study, performed in the CEA2 and INERIS3 laboratories, which deals with the development of LIBS technique for heavy metal particles measurements at very different concentrations in air or industrial exhausts. Indeed, LIBS can yield quantitative mass measurements of constituent species, enabling a direct, simultaneous measurement of aerosol particle mass and composition. Moreover, LIBS offers a rapid time response relative to the other techniques. The first part of this study is aimed at studying gases containing very low concentration particles. In order to measure such low concentrations, Cu particles, produced with an ultrasonic nebulizer (particle sizes > 1 m), are first collected and concentrated on quartz filters (Whatman QMA) and then analysed using a LIBS set-up. LIBS analyses were performed using laser wavelengths of 532nm and 266nm. Calibration curves were made in order to determine the limit of quantification of the particles on the filter. These values can be used to calculate for a given flux of particles the minimum delay for preconcentrating on the filter, and since the analysis is very fast, the delay between two following analyses.