APPLICATION OF SEMIPERMEABLE ION EXCHANGE MEMBRANES TO IN SITU DETERMINATION OF TRACE METAL IONS IN AQUEOUS SYSTEMS BY ELECTROCHEMICAL AND NEUTRON ACTIVATION TECHNIQUES - CRITICAL EVALUATION OF TECHNIQUES

Ion exchange membranes are employed in conjunction with neutron activation analysis and anodic stripping voltammetry to determine certain trace metal ions in aqueous media. As these two analytical techniques or applications with ion exchange membranes appear on the surface to have considerable promise with respect to in situ analysis in natural water systems, the parameters which govern their applicability, limitations, and sensitivity were investigated. This study showed these techniques to be somewhat impractical for routine trace analysis. The relationships (or proportionality factors) relating the measured amounts of material and the concentrations of these species in their original environment are complex, although they can be treated quantitatively. Furthermore, very long times are required for trace systems to reach equilibrium. In both analytical techniques, the ion exchange membrane is used as an in situ preconcentration matrix prior to actual analysis. Experiments were carried out to determine if large surface active organic materials in natural systems inhibit exchange by passivating or blocking the surface, which would make the analysis of nature systems impossible by this technique. © 1969, American Chemical Society. All rights reserved.