title: Bare and Polymer-Coated Indium Tin Oxide as Working Electrodes for Manganese Cathodic Stripping Voltammetry.
abstract: Though an essential metal in the body, manganese (Mn) has a number of health implications when found in excess that are magnified by chronic exposure. These health complications include neurotoxicity, memory loss, infertility in males, and development of a neurologic psychiatric disorder, manganism. Thus, trace detection in environmental samples is increasingly important. Few electrode materials are able to reach the negative reductive potential of Mn required for anodic stripping voltammetry (ASV), so cathodic stripping voltammetry (CSV) has been shown to be a viable alternative. We demonstrate Mn CSV using an indium tin oxide (ITO) working electrode both bare and coated with a sulfonated charge selective polymer film, polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene-sulfonate (SSEBS). ITO itself proved to be an excellent electrode material for Mn CSV, achieving a calculated detection limit of 5 nM (0.3 ppb) with a deposition time of 3 min. Coating the ITO with the SSEBS polymer was found to increase the sensitivity and lower the detection limit to 1 nM (0.06 ppb). This polymer modified electrode offers excellent selectivity for Mn as no interferences were observed from other metal ions tested (Zn(2+), Cd(2+), Pb(2+), In(3+), Sb(3+), Al(3+), Ba(2+), Co(2+), Cu(2+), Ni(3+), Bi(3+), and Sn(2+)) except Fe(2+), which was found to interfere with the analytical signal for Mn(2+) at a ratio 20:1 (Fe(2+)/Mn(2+)). The applicability of this procedure to the analysis of tap, river, and pond water samples was demonstrated. This simple, sensitive analytical method using ITO and SSEBS-ITO could be applied to a number of electroactive transition metals detectable by CSV.
authors.affiliation: Department of Chemistry, University of Cincinnati , Cincinnati, Ohio 45221-0172, United States.
authors.forename: Cory A
authors.initials: CA
authors.lastname: Rusinek
authors.affiliation: Department of Chemistry, Xavier University , Cincinnati, Ohio 45207-4221, United States.
authors.forename: Adam
authors.initials: A
authors.lastname: Bange
authors.affiliation: Department of Chemistry, University of Cincinnati , Cincinnati, Ohio 45221-0172, United States.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Warren
authors.affiliation: BioMicrosystems Lab, Department of Electrical Engineering and Computing Systems, University of Cincinnati , Cincinnati, Ohio 45221-0030, United States.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Kang
authors.affiliation: Department of Chemistry, University of Cincinnati , Cincinnati, Ohio 45221-0172, United States.
authors.forename: Keaton
authors.initials: K
authors.lastname: Nahan
authors.affiliation: BioMicrosystems Lab, Department of Electrical Engineering and Computing Systems, University of Cincinnati , Cincinnati, Ohio 45221-0030, United States.
authors.forename: Ian
authors.initials: I
authors.lastname: Papautsky
authors.affiliation: Department of Chemistry, University of Cincinnati , Cincinnati, Ohio 45221-0172, United States.
authors.forename: William R
authors.initials: WR
authors.lastname: Heineman
mesh_terms: D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D008345:Manganese / Q000032:analysis*; D011108:Polymers / Q000737:chemistry*; D013499:Surface Properties; D017971:Tin Compounds / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D011108:Polymers; D017971:Tin Compounds; D014874:Water Pollutants, Chemical; D008345:Manganese; C109984:indium tin oxide