Novel Copper(Ⅱ)-Selective Senor Based on a New Hexadentates Schiff's Base

A novel copper(II) membrane electrode based on diphenylisocyanate bis(acetylacetone) ethylenediimine (DIBAE), as a new hexadentates Schiff's base was prepared. The electrode exhibited a Nernstian response for Cu ²⁺ ions over a wide concentration range (1.0 × 10 ⁻¹ to 1.0 × l0 ⁻⁶ M) with a limit of detection of 6.0 × 10 ⁻⁷ M (39 ppb). The sensor shows a fast response time (15s) and the membrane can be used for more than 4 months without observing any major deviation. The electrode revealed very good selectivity with respect to many cations including alkali, alkaline earth, transition and heavy metal ions. The proposed sensor could be used in a pH range of 3.0-7.5. It was applied to the direct potentiometric determination of copper in black tea, and in wastewater of copper electroplating samples. The electrode was also used in potentiometric titration of the copper(II) ion with EDTA.