Automated determination of detection limits and selectivity coefficients of ion-selective electrodes by using a microcomputer-controlled potentiometric system

The detection limit and the potentiometric selectivity coefficients of ion-selective electrodes are determined automatically with a microcomputer-controlled potentiometric system. Measurements of these parameters for three commercially available electrodes of the liquid membrane type (chloride, nitrate and calcium electrodes) gave results in good agreement with those reported in the literature. The non-linear least-squares fit evaluation of data (potential activities) and the selection of the appropriate transfer functions are described. The reproducibility of the results is discussed.