Enhancement of selectivity of electrochemical detectors by kinetic discrimination in flow-injection systems

Appropriate design of pow-injection (FI) manifold and selection of suitable detectors may provide additional changes in the selectivity of the FI resp onse compared to conventional nonflow measurements. As an example of such s ystems, based on data from the literature and our own experimental data, th e potentiometric detection with different ion-selective electrodes and two different amperometric systems are discussed. Selectivity changes in flow-i njection analysis (FIA) systems for ion-selective membrane electrodes depen d on relative response to interferences observed in batch measurements. Sim ultaneous detection of pesticides is shown as an example of an amperometric FIA system with a bilayer lipid membrane working electrode. Simultaneous d etection of lactate and ascorbate is shown in an FIA system with amperometr ic biosensing detection. (C) 2000 John Wiley & Sons, Inc.