TY - JOUR
T1 - Electrochemical detection of As3+ and As5+ by anodic stripping voltammetry at a gold electrode
AU - Lestarini, D. T.
AU - Ivandini, T. A.
N1 - Funding Information:
Ac k n o wle d g e m e n ts This work was funded by PITTA Grant Universitas Indonesia with contract number 1822/UN2.R3.1/PPM.00.01/2017. The authors would like to thank Einago (www.einago.com) for the English language review.
Publisher Copyright:
© Published under licence by IOP Publishing Ltd.
PY - 2019/2/22
Y1 - 2019/2/22
N2 - In this article, electrochemical detection of arsenite (As3+) and arsenate (As5+) by stripping voltammetry at a gold electrode has been investigated. As3+ and As5• are reduced to arsine (AsH3) in 0.1 M sodium borohydride before deposition on the electrode surface. 0.1 M HCl was used as the supporting electrolyte, where Cl- ions act as an ionic bridge, facilitating reduction at the working electrode. As3+ and As5+ can be deposited as arsine by simple electrochemical reduction at -0.5 V (versus Ag/AgCl). Anodic stripping voltammograms of arsine at a gold electrode showed similar peak potentials for As° oxidation (≈0.31 V versus Ag/AgCl) under the optimum conditions (deposition potential, deposition time, and scan rate of -0.5 V, 60 s, and 200 mV/s, respectively). The stripping voltammograms for As3+ and As5+ presented similar peak shapes and current intensities. A reaction mechanism involving reduction to As0 at a mild potential in a strong acid, followed by oxidation of As° to As3+ at the gold electrode, was proposed. The method developed offers a wide linear concentration range for As3+ (0-5 ppm) and As5+ (0-20 ppm) and very low limits of detection for As3+ (0.85 ppm) and As5+ (6.07 ppm).
AB - In this article, electrochemical detection of arsenite (As3+) and arsenate (As5+) by stripping voltammetry at a gold electrode has been investigated. As3+ and As5• are reduced to arsine (AsH3) in 0.1 M sodium borohydride before deposition on the electrode surface. 0.1 M HCl was used as the supporting electrolyte, where Cl- ions act as an ionic bridge, facilitating reduction at the working electrode. As3+ and As5+ can be deposited as arsine by simple electrochemical reduction at -0.5 V (versus Ag/AgCl). Anodic stripping voltammograms of arsine at a gold electrode showed similar peak potentials for As° oxidation (≈0.31 V versus Ag/AgCl) under the optimum conditions (deposition potential, deposition time, and scan rate of -0.5 V, 60 s, and 200 mV/s, respectively). The stripping voltammograms for As3+ and As5+ presented similar peak shapes and current intensities. A reaction mechanism involving reduction to As0 at a mild potential in a strong acid, followed by oxidation of As° to As3+ at the gold electrode, was proposed. The method developed offers a wide linear concentration range for As3+ (0-5 ppm) and As5+ (0-20 ppm) and very low limits of detection for As3+ (0.85 ppm) and As5+ (6.07 ppm).
KW - anodic stripping voltammetry
KW - arsenate
KW - arsenic
KW - gold electrode
KW - sodium borohydride
UR - http://www.scopus.com/inward/record.url?scp=85066915247&partnerID=8YFLogxK
U2 - 10.1088/1757-899X/496/1/012030
DO - 10.1088/1757-899X/496/1/012030
M3 - Conference article
AN - SCOPUS:85066915247
VL - 496
JO - IOP Conference Series: Materials Science and Engineering
JF - IOP Conference Series: Materials Science and Engineering
SN - 1757-8981
IS - 1
M1 - 012030
T2 - 2nd International Conference on Current Progress in Functional Materials 2017, ISCPFM 2017
Y2 - 8 November 2017 through 9 November 2017
ER -