ESTIMATION OF ARSENIC IN GROUND WATER USING DIFFERENT VOLTAMMETRIC TECHNIQUES AT GOLD ELECTRODES. A COMPARATIVE STUDY

Arsenic ions in the groundwater of different parts of Bangladesh was estimated using different striping analysis techniques at gold button electrode and gold film on glassy carbon electrode. The Anodic StripingVoltammetric (ASV) methods were applied to measure low and high concentration of arsenic in ground water. The results of samples analysis clearly demonstrate that the electrochemical methods based on stripping analysis, with gold electrode are very sensitive and accurate to analyze As(III) and As(V) ionsdown to the level of -2 ppb. The average concentration of As(III) and As(V) ions in Dhaka City are 3.86 ppb and 0.94 ppb. These results indicate that the arsenic ions contamination are very low in the city. The relative concentration of As(III) ions are much higher than that of As(V) ions. Out of the four techniqueshave been used for arsenic analysis, Square Wave Anodic Striping Voltammetry (SWASV) is most sensitive and selective method because of its ability to enhance the analytical signal by removing nonfaradic current.