Stripping Voltammetric Determination of Zirconium with Complexing Preconcentration of Zirconium(IV) at a Morin‐Modified Carbon Paste Electrode

A sensitive, selective and economic stripping voltammetry is described for the determination of trace amounts of zirconium at a morin‐modified carbon paste electrode (morin‐MCPE). Zirconium(IV) can be preconcentrated on the surface of the morin‐MCPE due to forming the Zr(IV)–morin complex. The complex produces two second‐order derivative anodic peaks at 0.69 V (vs. SCE) and 0.75 V when linear‐scanning from 0.0 to 1.0 V. The optimum analytical conditions are: 2.2 mol L −1 HCl, 0.0 V accummulation potential, 90 s accummulation time, 250 mV s −1 scan rate. A linear relationships between the peak currents at 0.75 V and the Zr(IV) concentration are in the range of 2.0×10 −8 to 3.0×10 −6 mol L −1 . The detection limit is 1.0×10 −8 mol L −1 (S/N=3) for 120 s accumulation. The RSD for determination of 4.0×10 −7 mol L −1 Zr(IV) is 4.8% ( n =8). The proposed method has been applied to determine zirconium in ore samples, unnecessarily extracted.