Determination of Arsenic(III) Using Platinum Nanoparticle-Modified Screen-Printed Carbon-Based Electrodes

The electrochemical detection of arsenic(III) was investigated on platinum nanoparticle-modified carbon-based screen-printed electrodes (PtNPs/SPCEs) in 1 M aqueous H2SO4. PtNPs/SPCEs were prepared by electrochemical deposition of K2PtCl6. The resulting electrode surfaces were characterized with scanning electron microscopy (SEM). By using the As(III) oxidation peak for the analytical determination, there is no interference from Cu(II) if present in contrast to the other metal surfaces typically used for the detection of arsenic in electrochemistry. Precision of the proposed method was very good and a relative good accuracy determined by analysis of a certificate sample and in a spiked tap water sample. Electroinactive As(V) was reduced to As(III) by sodium thiosulfate prior to determination. The detection limit for As(III) obtained was 5.68 mu g L-1. In terms of reproducibility, the precision of the above mentioned method in % RSD was calculated at 2.27%.