Potentiometric Stripping of Arsenic(III) Using a Wall-Jet Flow Cell and Gold(III) Solution as Chemical Reoxidant

• Published in: Electroanalysis (New York, N.Y.) N.Y.), 2004-09, Vol.16 (18), p.1528-1535
• Main Authors: Muñoz, Emma, Palmero, Susana
• Format: Article
• Language: English
• Subjects: Arsenic(III); Co-deposition of Au(III) and As(III); Potentiometric stripping analysis; Wall-jet flow Cell
• ISSN: 1040-0397; 1521-4109
• DOI: 10.1002/elan.200302981

In the proposed method As(III) is determined with a wall‐jet flow cell by means of potentiostatic co‐deposition of Au(III) and As(III) at a glassy‐carbon electrode and subsequent chemical stripping with Au(III). Factors affecting sensitivity and precision including acidity, Au(III) concentration, electrodeposition potential and flow rate were optimized. Optimum determination of As(III) in solutions containing 160 mg L−1 and 1.2 M hydrochloric acid was accomplished with an electrolysis potential of −0.1 V (vs. Ag/AgCl) and a flow rate of 0.59 mL min−1. Different linear concentration ranges were achieved under these conditions with good precision and relative standard deviations between 6–9%. The detection limit obtained after 120 s of electrolysis was 0.55 μg L−1.