A Novel Carbon Paste Electrode for Potentiometric Determination of Vanadyl Ion
نویسندگان
1 Department of Chemistry, Faculty of Samen Hojaj, Technical and Vocational University, Tehran, I.R. IRAN
2 Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, I.R. IRAN
3 Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, I.R. IRAN
4 Department of Biochemistry, National Research Institute for Genetic Engineering and Biotechnology, Tehran, I.R. IRAN
5 Department of Chemistry, Neyshabour Science and Research Branch, Islamic Azad University, Neyshabur, I.R. IRAN
6 Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, I.R. IRAN
7 Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, I.R. IRAN
doi
10.30492/ijcce.2015.15460چکیده
Carbon paste electrode was modified by disodium 2,4-diamino-7-methylbenzo[g] pteridine-5,10-dioxide to fabricate a sensor for potentiometric determination of vanadyl ion (VO2+) in aqueous medium. The new ligand was synthesized in three steps with high yield. The optimal composition of the carbon paste was made of graphite powder (64.5%), ionophore (16.6%), paraffin oil (17.8%), and sodium tetraphenylborate (NaTPB, 1.1%). The electrode exhibited a constant sensitivity of 30.20 ± 0.5 mV to VO2+ ions over a concentration range of 5 mM to 1 mM. The detection limit was calculated to be 5 mM with a response time of less than 35 s. The electrode showed to be highly reproducible over a period of 3 weeks. This sensor exhibits high selectivity to VO2+ ions and was successfully employed for potentiometric titration of VO2+ ions with EDTA.
