Nasser, H.N., Issa, Y.M. . and Khalel, M.B. 2016. Preparation of a New selective PVC Membrane Electrode for Copper(II) Ion Based on Complex of 1,3-diphenyl-5- (P-nitrophenyl) Formazan as Ionophore with Copper(II). Tishreen University Journal -Basic Sciences Series. 37, 1 (May 2016).