A comparison of cloud chambers for use in inductively coupled plasma nebulisation systems

Abstract

A comparison of the analytical performance of five cloud chambers of different geometry used in conjunction with a commercial concentric glass nebuliser is reported. The comparison was based on measurements of transport efficiency, background equivalent concentration, analyte emission stability, detection limit, equilibration time and memory effect. Significant variations in performance indicated the importance of cloud chamber geometry on the nebulisation system. Best results were obtained with a new design based on a cylindrical chamber with a central tangential inlet. Droplet size distribution measurements revealed that although the primary distribution of the nebuliser aerosol contained a substantial proportion of small droplets of similar size to those in the ultimate distributions of the nebulisation systems, a large number of droplets are removed from the aerosol by separation processes occurring in the chambers.