Abstract
The enhancement of the concentration of analytes by a feed/receiving volume effect in coupled membrane transport was both theoretically and experimentally investigated in view of the designs of uphill transport membrane sensors and novel preconcentration techniques in general. Theoretical equations for the feed/receiving volume effect were derived for the membrane diffusion-limited co-transport and counter transport cases. The theoretical results coincided well with the volume effect observed experimentally for some representative liquid membrane systems, in which the concentration of an analyte in the receiving solution was found to increase upon decreasing the volume of the receiving (inner filling) solution. The complexation reaction of an analyte in the receiving solution was found to be useful as an additional driving force for further enhancing the analyte concentration by coupled transport.
