నైరూప్య

Differential Pulse Anodic Stripping Voltammetric Determination Of Mercury (II) In Natural Water At A Carbon Paste Electrode Modified With Organofunctionalized Amorphous Silica

�?�?�?�?�?�?�?�?der T.G.Cavalheiro, Glimaldo Marino, Ivana Cesarino

The determination of mercury using a carbon paste electrode modified with organofunctionalized amorphous silica with 2-benzothiazolethiol was investigated. The Hg (II) oxidation peak was observed around 0.080 V (vs. SCE) in potassium chloride solution 0.1 mol L-1 (pH 2.0) in differential pulse anodic stripping voltammetry. The best results were obtained under the following optimized conditions: 2 minute accumulation time, 50 mV pulse amplitude, 5 mV s-1 scan rate in potassium chloride solution 0.1 mol L-1 pH 2.0. Using such parameters four linear dynamic regions could be observed for the anodic peak current at the Bzt-CPE in relation to the concentration of the Hg(II) in a range from 8.24·x 10-7 to 9.88·x 10-5 mol L-1. Hg (II) spiked in a natural water sample was determined with 99.1% mean recovery (n=3) at 10-6 mol L-1 level. Interference from cationic species was also evaluated.