WET EFFLUENT DENUDER COUPLED LIQUID ION CHROMATOGRAPHY SYSTEMS

The titled instrumentation involves an absorber liquid flowing down the inner walls of a tube while sample gas flows countercurrent upward. The liquid is fully aspirated at the bottom and injected, along with small amounts of air, periodically into a chromatographic system. The presence of the air in the injected sample does not degrade chromatographic performance. Four distinct designs of the wet denuder are described and performance data for one type, coupled to a suppressed IC system, are presented for the determination of SO2. Good collection efficiency and excellent reproducibility are observed. In laboratory studies, the estimated detection limits are in the single digit pptrv range for a 7-min sample. Such diffusion-based collection/analysis systems with continuously renewed collection surfaces are expected to be generally applicable for the measurement of trace atmospheric gases.