EVALUATION OF A DEMOUNTABLE TANGENTIAL FLOW TORCH FOR MICROWAVE-INDUCED PLASMA-ATOMIC EMISSION-SPECTROMETRY

A demountable torch for the microwave-induced plasma that utilizes a t angential flow pattern is described. This new torch is compared to a c onventional all-quartz design in a series of comparative studies. Diag nostic studies consist of measurements of electron number densities, e xcitation temperatures, and ionization temperatures of an argon plasma generated in each torch. Hydrodynamic flow measurements, vertical emi ssion profiles, and limits of detection provide further contrast betwe en the characteristics of the demountable design and conventional all- quartz torch. The compatibility of the new torch design with supercrit ical CO2 flows is demonstrated where the MIP is coupled with a packed- column supercritical fluid chromatograph for the purpose of element-sp ecific detection. The physical advantages of the demountable torch ove r the all-quartz design are discussed.