title: Development of a pH sensing membrane electrode based on a new calix[4]arene derivative.
abstract: A new pH sensing poly(vinyl chloride) (PVC) membrane electrode was developed by using recently synthesized 5,17-bis(4-benzylpiperidine-1-yl)methyl-25,26,27,28-tetrahydroxy calix[4]arene as an ionophore. The effects of membrane composition, inner filling solution and conditioning solution on the potential response of the proposed pH sensing membrane electrode were investigated. An optimum membrane composition of 3% ionophore, 67% o-nitrophenyl octyl ether (o-NPOE) as plasticizer, 30% PVC was found. The electrode exhibited a near-Nernstian slope of 58.7±1.1 mV pH(-1) in the pH range 1.9-12.7 at 20±1 °C. It showed good selectivity for H(+) ions in the presence of some cations and anions and a longer lifetime of at least 12 months when compared with the other PVC membrane pH electrodes reported in the literature. Having a wide working pH range, it was not only applied as a potentiometric indicator electrode in various acid-base titrations, but also successfully employed in different real samples. It has good reproducibility and repeatability with a response time of 6-7s. Compared to traditional glass pH electrode, it exhibited excellent potentiometric response after being used in fluoride-containing media.
authors.affiliation: Department of Chemistry, Faculty of Science, Ankara University, Tandoğan, 06100 Ankara, Turkey. Electronic address: kormali@science.ankara.edu.tr.
authors.forename: H Elif
authors.initials: HE
authors.lastname: Kormalı Ertürün
authors.affiliation: Department of Chemistry, Faculty of Science, Ankara University, Tandoğan, 06100 Ankara, Turkey.
authors.forename: Ayça
authors.initials: A
authors.lastname: Demirel Özel
authors.affiliation: Department of Chemistry, Faculty of Science, Selçuk University, Selçuklu, 42075 Konya, Turkey.
authors.forename: Serkan
authors.initials: S
authors.lastname: Sayın
authors.affiliation: Department of Chemistry, Faculty of Science, Selçuk University, Selçuklu, 42075 Konya, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Yılmaz
authors.affiliation: Department of Chemistry, Faculty of Science, Ankara University, Tandoğan, 06100 Ankara, Turkey.
authors.forename: Esma
authors.initials: E
authors.lastname: Kılıç
mesh_terms: D047250:Calixarenes / Q000737:chemistry*; D004987:Ethers / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D017736:Ion-Selective Electrodes; D007476:Ionophores / Q000737:chemistry*; D008567:Membranes, Artificial; D011143:Polyvinyl Chloride / Q000737:chemistry; D011199:Potentiometry / Q000379:methods*; D011522:Protons
chemical_list: C519952:2-nitrophenyl octyl ether; D004987:Ethers; D007476:Ionophores; D008567:Membranes, Artificial; D011522:Protons; D047250:Calixarenes; D011143:Polyvinyl Chloride
keywords: Calix[4]arene; Potentiometry; Titratable acidity; pH measurement; pH sensing PVC membrane electrode