A Serial Array of ISEs for use in a Portable Battery-Powered Flow Injection Analyzer

Portable flow injection potentiometry (FIP) is described with a flow-through multi-ion sensor array system based on a planar design. Potassium, sodium and nitrate sensors are used as examples for simultaneous multi-ion determinations based on the availability of a planar sensor design for these ions. The miniaturized flow cell developed with the three sensors in series in the FIP system is used to demonstrate the reliability of this portable design when using manual injection of the sample solution. The system is characterized by its small size, light weight and low power requirements, and makes use of a notebook computer for real-time display of data and data acquisition. Rapid FIP response characteristics are shown after optimization of flow carrier conditions, and are successfully applied to the analysis of mineral water samples.