Ionic Liquids Improve Analytical Parameters of Cadmium Ion-Selective Electrodes with Solid Contact

Potentiometric properties of cadmium ion-selective electrodes with solid contact based on polymeric membrane doped with ionic liquid (IL) were investigated. Basic analytical parameters of the electrodes, such as detection limit, linear range, slope characteristic, response time and pH dependence of the electrode potential, as well as selectivity coefficients in relation to some inorganic cations were determined. The addition of ILs to the membrane phase was found to improve the analytical parameters of the studied electrodes. Electrodes containing them in the membrane exhibit a lower detection limit to improve by about one order of magnitude, shorter response time of about 5 s, wider pH range and improvement selectivity in comparison to the electrode without ionic liquid. The best results were obtained for the electrode having its membrane doped with 1-ethyl-3-methylimidazolium chloride (EMlmCl) and 1-butyl-3-methylimidazolium chloride (BMlmCl).