VOLTAMMETRIC LITHIUM ION-SELECTIVE ELECTRODES BASED ON ION TRANSFER AT THE OIL WATER INTERFACE FACILITATED BY NEUTRAL IONOPHORES/

Voltammetric measurements were performed for the transfers of Li+ and Na+ at an oil/water interface facilitated by neutral ionophores includ ing 14-crown-4 derivatives. For the organic solvent, nitrobenzene, o-n itrophenyloctylether (NPOE) and o-nitrophenylphenylether (NPPE) were e xamined. The interface between water and NPPE containing 20 mM dibenzy l-14-crown-4 was found to serve best for the ion-selective-electrode ( ISE) surface for the voltammetric determination of Li+. A test of this voltammetric Li+-ISE using artificial serum showed that the interfere nce from a large amount (ca. 140 mM) of Na+ in blood can be easily avo ided by detecting the Na+ concentration simultaneously with the same e lectrode.