Ion-selective electrodes with liquid membranes

Different kinds of partition equilibria are found in chemical sensors. In sensors on the basis of ion-selective electrodes with liquid membranes, specific ligands are dissolved which form complexes with sample ions. In this way, at the sensor surface a concentration-dependent galvani potential difference is formed which can be measured potentiometrically. The principle of extraction photometry is applied, in modified manner, in optical sensors. Extraction photometry is a classical method of trace analysis, where the sample solution is extracted using a water-immiscible solution of a ligand which is able to... 

Figure7.6. Ion-selective electrodes with liquid membrane...

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