Coated-wire and coated-disc Cu(II) ion-selective electrodes based on Cu(II) complex with cyclized salophen

Coated-wire and coated-disc ion selective electrodes (ISE) based on cyclized N,N'-bis(salicylidene)-o-phenylenediamine (salophen) complex with Cu(II) were fabricated for determination of Cu(II) in aqueous solutions. The response of the ISE was optimized by variation of membrane composition and evaluation of the various experimental conditions. Near Nernstian slopes (similar to28mV/decade) were obtained. The linear range of the ISE ranged from 5 x 10(-5) to 1 x 10(-2) M Cu(II). The potentiometric selectivity coefficients (K-ij) were determined for Na+, NH4+, Ca2+, Mg2+, Ni2+, Pb2+, Zn2+, Cd2+, Co2+, Fe3+, Hg2+, CO32-, H2PO4-, H2PO42-, SO42-, CH3OO-, Br-, I-, NO3-, and SCN-. The selectivity coefficients were in the range from 10(-2) to 10(-3) for all ions tested except Hg2+, I-, and to less extent Fe3+. The fabricated ISE using the Cu(II)-salophen complex are reliable and stable.