Development of an analytical method for the electrochemical determination of total As using the Rodeostat and gold working electrodes.

(a) The influence of deposition potential on the height of the arsenic stripping peak (single scans and the average of two repeat experiments using screen-printed electrodes, and three repeat scans in a single experiment using microwire electrodes). (b) The effect of deposition time on the height of the arsenic stripping peak using printed electrodes (single scans using screen-printed electrodes and triplicate scans using microwire electrodes). (c) Background-subtracted voltammograms with increasing arsenic concentrations obtained using screen-printed electrodes and (d) the calibration curve highlighting the linear range. (e) Background-subtracted voltammograms with increasing arsenic concentrations obtained using microwire electrodes and (f) the calibration curve highlighting the linear range. Open shapes indicate data points outside the linear range. The data presented in (c) and (d) are the results of a single scan only (due to limited electrode stability), whilst the data presented in (e) and (f) is the average of three repeat scans. Error bars indicate the standard deviation between repeat measurements. The microwire electrode results presented in (b) were obtained using the PalmSens 2 potentiostat. All measurements were performed in 0.1 M HCl (pH 1).