Adsorption Stripping Voltammetric Determination of Trace Amounts of Mercury with Polyphenylfluorone Modified Glassy Carbon Electrode

A polyphenylfluorone modified glassy carbon electrode (PPF-GCE) was prepared by electropolymerization,and used in the adsorption stripping voltammetric determination of traces of mercury.In a 0.1 mol·L-1 ammoniacal buffer solution of pH 9.5,and under the condition of open circuit,Hg(Ⅱ) ion was accumulated (in 5 min) on the surface of the modified electrode by forming a complex with phenylfluorone.After changing the medium from ammoniacal solution to 0.1 mol·L-1 HCl solution,in which Hg(Ⅱ) was reduced at -0.40 V,and anodic potential scanning was carried out starting from -0.4 V in the positive direction a sensitive peak of mercury due to anodic stripping was observed around 0 V.Values of oxidative peak current of mercury was found to keep linear relationship with its concentration in the range of 9.0×10-8-8.0×10-7mol·L-1,with its detection limit of 2.0×10-8mol·L-1.The proposed method has been applied to the determination of mercury in urine samples,giving average value of RSD′s less than 4.02%,and values of recovery in the range from 98.4% to 103.2%.