Low-cost electrochemical instrumentation for the detection of arsenic used in this work.

In this case, the gold microwire set-up is presented. The Rodeostat potentiostat (in the transparent plastic housing at the back of the image) is connected to the electrodes via a shielded ethernet cable. The electrodes are mounted in a 3D printed plastic lid with an extra opening port for addition of the arsenic standard solution via pipette (to avoid knocking the electrode connections). The electrodes are (left) iridium wire counter electrode, (centre) Ag/AgCl/KCl (3M) reference electrode, and (right) gold microwire working electrode assembled with a mechanical vibrator. The 40 mL sample cell is positioned on top of a magnetic stirrer plate for mixing after addition of the sample and As(V) standard solution and possibly during the deposition stage (to increase mass transfer).