title: Development of a new chemically modified carbon paste electrode for selective determination of urinary and serum oxalate concentration.
abstract: The construction and evaluation of a novel modified carbon paste electrode with high selectivity toward oxalate ion are described. The constructed carbon paste potentiometric sensor for oxalate ion is based on the use of a zirconium salan complex as a good ionophore in the carbon paste matrix. The electrode exhibits a Nernstian slope of 29.1 mV/decade to oxalate ion over a wide concentration range from 1.5×10(-6) to 3.9 ×10(-2) mol L(-1) with a low detection limit of 7.0×10(-7) mol L(-1). The electrode possesses fast response time, satisfactory reproducibility, appropriate lifetime, and most importantly, good selectivity toward C2O4(2-) relative to a variety of common anions. The potentiometric response of the electrode is independent of the pH of the test solution in the pH range 2.5-8.0. The modified carbon paste electrode was successfully applied as an indicator electrode in potentiometric titration and potentiometric determination of oxalate ion in mineral water, blood serum and urine samples.
authors.affiliation: School of Chemistry, Damghan University, Damghan 3671641167, Iran; Institute of Biological Science, Damghan University, Damghan 3671641167, Iran. Electronic address: soleymanpour@du.ac.ir.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Soleymanpour
authors.forename: Bita
authors.initials: B
authors.lastname: Shafaatian
authors.forename: Homeira Sadat
authors.initials: HS
authors.lastname: Mirfakhraei
authors.forename: Abdolreza
authors.initials: A
authors.lastname: Rezaeifard
mesh_terms: D000838:Anions; D002244:Carbon / Q000737:chemistry*; D004566:Electrodes; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007476:Ionophores; D057230:Limit of Detection; D008900:Mineral Waters / Q000032:analysis*; D009942:Organometallic Compounds; D010070:Oxalates / Q000097:blood / Q000652:urine; D011199:Potentiometry / Q000379:methods*; D015203:Reproducibility of Results; D015040:Zirconium
chemical_list: D000838:Anions; D007476:Ionophores; D008900:Mineral Waters; D009942:Organometallic Compounds; D010070:Oxalates; D002244:Carbon; D015040:Zirconium
keywords: Carbon paste electrode; Oxalate; Potentiometry; Sensor; Zirconium complex