▎ 摘　　要

A citrate selective coated graphite electrode (CGE) based on zinc monoamino-phthalocyanine functionalized graphene (ZnMAPc-G) has been developed and potentiometrically evaluated. The composition of the membrane prepared from ZnMAPc-G, DOS, and PVC in THF was optimized. The sensor based on ZnMAPc-G containing 5 % ZnMAPc possessed the optimum performance in glycine buffer 0.01 M of pH 3.9 with a near Nernstian slope of -57.3+/-0.5 mV/decade, a linear range of 8 x 10(-7)-1 x 10(-2) mol L-1 and a detection limit of 5 x 10(-7) mol L-1. Different electrodes prepared using ZnMAPc as free ionophore or as composite with graphene (ZnMAPc/G) were also evaluated and compared to the electrode containing covalently attached ionophore (ZnMAPc-G). The proposed sensor possessed a long-life of about 6 months without notable drift in its slope and was utilized in the determination of the citrate concentration in some pharmaceutical formulation.