A new triiodide ion-selective electrode based on a charge-transfer complex of iodine with ditertbutyldicyclohexyl-18-crown-6 t-Bu)2DC18C6 as membrane carrier was prepared. The electrode has a linear) dynamic range from 6.3 x 10-3-5 x 10-6 with a Nernstian response of 58.6 + 1 mV decade-1 and a detection limit of 1.3 x 10-6 M. The response time of the sensor was 25 s. The membrane could be used for two months without any divergence in potentials. The electrode exhibits an anti-Hofmeistetr selectivity sequence with a preference for triiodide at pH 2.0-10.0. The responsemechanismof the electrode was investigated by Uv-Vis spectroscopic technique. The electrode can be used for the determination of ascorbic acid in orange juice
