title: Amperometric determination of sulfide based on its electrocatalytic oxidation at a pencil graphite electrode modified with quercetin.
abstract: This study describes a new approach for the investigation of electrocatalytic oxidation of sulfide using a pencil graphite electrode modified with quercetin (PGE/QH(2)). Adsorption procedure was used for the preparation of the modified electrodes. It was observed that PGE/QH(2) showed a significant electrocatalytic activity toward sulfide oxidation. Cyclic voltammetric studies show that the peak potential of sulfide shifts from +450 mV at bare PGE to +280 mV at PGE/QH(2). The electrocatalytic currents obtained from amperometric measurements at +300 mV vs. Ag/AgCl/KCl(sat) and at pH 8.0 BR buffer solution containing 0.1M NH(4)Cl were linearly related to the concentration of sulfide. The calibration graph consisted of two linear segments of 1-20 μM and 20-800 μM with a detection limit of 0.3 μM (based on 3s(b)). The proposed method was successfully applied to the determination of sulfide in waste waters and was compared with the spectrophotometric method.
authors.affiliation: Çanakkale Onsekiz Mart University, Science & Art Faculty, Department of Chemistry, 17100 Çanakkale, Turkey. ydilgin@yahoo.com
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Dilgin
authors.forename: Bayram
authors.initials: B
authors.lastname: Kızılkaya
authors.forename: Bensu
authors.initials: B
authors.lastname: Ertek
authors.forename: Nuri
authors.initials: N
authors.lastname: Eren
authors.forename: Didem Giray
authors.initials: DG
authors.lastname: Dilgin
mesh_terms: D000327:Adsorption; D000643:Ammonium Chloride / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods; D002021:Buffers; D002138:Calibration; D004563:Electrochemistry; D004566:Electrodes; D006108:Graphite / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D010084:Oxidation-Reduction; D011794:Quercetin / Q000737:chemistry*; D013053:Spectrophotometry; D013440:Sulfides / Q000032:analysis*; D014865:Waste Disposal, Fluid; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D002021:Buffers; D013440:Sulfides; D014874:Water Pollutants, Chemical; D000643:Ammonium Chloride; D014867:Water; D006108:Graphite; D011794:Quercetin