COMMENT ON WET EFFLUENT DENUDER COUPLED LIQUID ION CHROMATOGRAPHY SYSTEMS - ANNULAR AND PARALLEL-PLATE DENUDERS

Simon and Dasgupta (Simon, P. IK.; Dasgupta, P. K. Anal. Chem. 1993, 65, 1134-1139) have reported on the design and characterization of high-efficiency wetted denuders of parallel plate and annular geometries. On the basis of laboratory results evaluated according to a theoretical treatment which refers to previous literature, they found that a ''supertheoretical'' collection efficiency was exhibited by the parallel plate denuder. It was found that a factor of 2 should be taken into account in the expression which describes the diffusion-based collection efficiency. By using the correct formula, the parallel plate denuder shows an excellent agreement to the theoretical efficiency curve. Discrepancies noted in the paper for the annular denuder and possible explanations for them have also been discussed.