Determination of Arsenic(III) at a Nanogold Modified Solid Carbon Paste Electrode

A selective and sensitive electroanalytical method was developed for arsenic determination based on a nanogold (AuNP) modified solid carbon paste working electrode (SCPE) modified in two steps (i) physisorption and (ii) additional electrodeposition of nanogold particles in the presence of iodide. Copper(II) interference was solved by covering the gold layer by a self assembled mono layer (SAM) of glutathione. Using DPASV a linear response of the signal was obtained as a function of As(III) in the concentration range 0.05-20 mu M (4-1498 ppb) with a limit of detection of 0.01 mu M (0.9 ppb). Sample stirring and degassing were not needed. Application to the determination of arsenic(III) and (V) in underground water samples from Burkina Faso was successfully achieved.