FLOW-INJECTION ANALYSIS OF POTASSIUM USING AN ALL-SOLID-STATE POTASSIUM-SELECTIVE ELECTRODE AS A DETECTOR

The concentration of potassium was determined by a combination of flow injection analysis (FIA) with an all-solid-state potassium sensor det ection. The all-solid-state potassium-selective electrode possessing l ong-term potential stability was fabricated by coating an electroactiv e polypyrrole/poly(4-styrenesulfonate) film electrode with a plasticiz ed poly(vinyl chloride) membrane containing valinomycin. The simple FI A system developed in this laboratory demonstrated sensitivity identic al to that in the batch system and achieved considerably rapid assay ( 150 samples h(-1)). Analyses of soy sauce and control serum samples by this FIA system yielded results in good agreement with those obtained by conventional measurements. (C) 1998 Elsevier Science B.V. All righ ts reserved.