COMPARISON OF STRIPLINE SOURCE AND ENHANCED BEENAKKER MICROWAVE CAVITY DESIGNS FOR ATOMIC EMISSION-SPECTROMETRY

An 'enhanced' Beenakker cavity (EBC) and a stripline source (SLS) are evaluated with a modified, commercially available electrothermal vaporizer for sample introduction. The analytical figures of merit reported for two elements (Cd and Cu) determined under optimal conditions are comparable for the two sources. The SLS supports aqueous vapour introduction without disturbing the discharge. For the SLS Na matrix interference is an order of magnitude less severe than with the EBC. The SLS was also operated at 90 W with a conventional pneumatic nebulizer for aqueous aerosol introduction. Overall, the SLS is simple to use, tolerant of high water (mass) loading and inexpensive to construct; it exhibits high coupling efficiency and stable operation over a wide range of generator power levels and flow conditions. Its detection limits are comparable to other microwave source designs.