Determination of arsenic (III) at a nano gold 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 work- ing electrode (SCPE) modified in two steps (i) physisorp- tion and (ii) additional electrodeposition of nanogold par- ticles 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 0.05–20mM (4– 1498 ppb) with a limit of detection of 0.01 mM (0.9 ppb). Sample stirring and degassing were not needed. Applica- tion to the determination of arsenic(III) and (V) in un- derground water samples from Burkina Faso was success- fully achieved.