title: Method development for the determination of arsenic by sequential injection/anodic stripping voltammetry using long-lasting gold-modified screen-printed carbon electrode.
abstract: An automated method has been developed for determining the concentration of inorganic arsenic. The technique uses sequential injection/anodic stripping voltammetry with a long-lasting gold-modified screen-printed carbon electrode. The long-lasting gold electrode was electrochemically deposited onto a screen-printed carbon electrode at a potential of -0.5 V vs. Ag/AgCl in a supporting electrolyte solution of 1M hydrochloric acid. Under optimal conditions and the applied potentials, the electrode demonstrated that it can be used for a long time without a renewal process. The linear range for the determination of arsenic(III) was 1-100 μg L(-1), and the limit of detection (LOD) in standard solutions was as low as 0.03 μg L(-1) for a deposition time of 120 s and sample volume of 1 mL. This method was used to determine the concentration of arsenic(III) in water samples with satisfactory results. The LOD in real samples was found to be 0.5 μg L(-1). In addition, speciation between arsenic(III) and arsenic(V) has been achieved with the proposed method using deposition potentials of -0.5 V and -1.5 V for the determination of the arsenic(III) concentration and the total arsenic concentration, respectively; the results were acceptable. The proposed method is an automated system that offers a less expensive alternative for determining trace amounts of inorganic arsenic.
authors.affiliation: Electrochemistry and Optical Spectroscopy Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Road, Pathumwan, Bangkok 10330 Thailand; Graduate School of Natural Science and Technology, Okayama University, Tsushimanaka 1-1-1, Kitaku, Okayama 700-8530, Japan.
authors.forename: Eakkasit
authors.initials: E
authors.lastname: Punrat
authors.forename: Suchada
authors.initials: S
authors.lastname: Chuanuwatanakul
authors.forename: Takashi
authors.initials: T
authors.lastname: Kaneta
authors.forename: Shoji
authors.initials: S
authors.lastname: Motomizu
authors.forename: Orawon
authors.initials: O
authors.lastname: Chailapakul
mesh_terms: D001151:Arsenic / Q000032:analysis*; D002244:Carbon / Q000737:chemistry; D055664:Electrochemical Techniques; D004566:Electrodes; D017022:Flow Injection Analysis; D005618:Fresh Water / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D010084:Oxidation-Reduction; D011327:Printing; D018030:Silver Compounds / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D018030:Silver Compounds; D014874:Water Pollutants, Chemical; D002244:Carbon; D006046:Gold; C037548:silver chloride; D001151:Arsenic
keywords: Anodic stripping voltammetry; Arsenic determination; Long-lasting electrode; Screen-printed carbon electrode; Sequential injection analysis