Lithium Ion-Selective Electrode

Ion-selective electrodes have been widely used in medicine as a tool for measuring alkali and alkaline earth metal ions in blood. This method, using the ion-selective electrodes, is excellent in simplicity and economy because the target ions are determined by simply immersing the electrode into the sample without any pretreatment.

Much attention has also been focused on Li⁺-selective electrodes. The 1,10-Phenanthroline derivative 1 is a neutral carrier for lithium ion-selective electrodes. PVC membrane electrodes based on 1 exhibit excellent Li⁺-selectivity and the selectivity coefficients for Li⁺ relative to the other metal ions are: Na⁺(-3.1), K⁺(-3.3), Ca²⁺(-3.2), Mg²⁺(-3.0)(logK). These values are similar or higher than those with 14-crown-4 derivatives which have been under study for some time.

Therefore an electrode based on 1 is a good candidate for clinical applications.