Vertically positioned axially viewed aerosol cooled plasma - a new design approach for microwave induced plasma optical spectrometry with solution nebulization

A vertically positioned axially viewed argon microwave induced plasma (Ar-MIP) system is described, which can serve as a spectrochemical excitation source. The design concept of improved TE101 rectangular cavity based on strong coupling between the plasma load and the magnetron generator has been presented. The idea of plasma cooling with a pure water aerosol is explained. The torch cooling system which permits aerosol generation and circulation has been described in detail. The influence of cooling on the argon plasma positioning in the discharge tube was investigated. The spectroscopic temperatures of iron and argon have been measured to evaluate excitation conditions and effect of plasma cooling. Analytical performance of the presented MIP system was characterized by determination of the limits of detection for some elements and comparison with other Ar-MIP experimental setups. Analysis of certified reference material was performed to determine the accuracy and precision available with the presented system. (C) 1999 Elsevier Science B.V. All rights reserved.