On-line analysis of elemental pollutants in gaseous effluents by inductively coupled plasma optical emission spectrometry: thermodynamic aspects

A method has been developed for the direct analysis of pollutant elements in gases, using a classical analytical inductively coupled plasma (ICP). The direct injection of a gaseous sample into a classical argon ICP allows the determination of the metallic elements carried by the gas. A thermodynamic study has shown the need to control the water content of the gas being analysed. A special torch, able to withstand the dramatic increase in thermal conductivity, has been designed. Calibration was carried out by means of a standard aerosol. This aerosol was produced using a standard solution, a batch-type ultrasonic nebulizer and a desolvation unit. Detection limits were determined in air for several heavy metals and toxic elements: these ranged from 25 µg m–3(As) to less than 1 µg m–3(Cu, Cr, Fe, Mn, Ti and Zn). These detection limits are lower than the threshold limit values in the gaseous effluents of incineration and other industrial plants.