Operational Assessment of a Potentiometric Eight-Sensor Flow Cell in a Portable Flow Injection Analyzer

The evaluation of a novel eight-sensor flow cell used in a portable battery-powered flow injection potentiometry system is described. The portable flow injection system is small in size, light weight, requires low power, and uses a notebook computer for real-time display of data and data acquisition, making it practical for remote site monitoring. The electrode response for each sensor was evaluated in terms of flow rate and injection sample volume with silver and iodide standard solutions, each in a 0.1-M sodium acetate background. The mean electrode slopes observed for silver and iodide ions were 57.4 ± 1.0 and 47.5 ± 4.4 mV per activity decade, respectively. Potential applications include multiion capability with eight different liquid-membrane-based electrodes or operation of the measuring electrodes in an additive mode for improved sensitivity and detection limit for a single analyte. © 1996 John Wiley & Sons, Inc.