Determination of Copper Content of Human Blood Plasma by an Ion Selective Electrode based on a New Copper-Selectophore

A new selectophore was introduced for Cu2+ ions. Spectroscopic studies showed a selectivity of a new organic compound (L) toward copper ions and several transitional metal ions. Hence, L was utilized in designing several ion selective electrodes for these cations. In practice, Cu2+ ion selective electrode behaved Nernstian (slope of 27.95±0.3 mV decade-1) over a wide linear range of 1.0×10-6-1.0×10-2 mol L-1. Optimum performance of the indicator electrode was observed by a membrane containing 7% selectophore, 2% sodium tetraphenyl borate (NaTPB) as an ionic additive, 61% nitrobenzene (NB) as solvent mediator and 30% polyvinyl chloride (PVC). The sensor showed a short response time of about 20 s and an acceptable life time, the potentiometric response is independent on the pH of the solution in the range of 3.5-7. The optimized copper sensor was used for analysis of copper content of some blood plasma samples. The obtained results were in good agreements with ICP-OES method.