title: Sulfate-selective PVC membrane electrode based on a strontium Schiff's base complex.
abstract: A strontium Schiff's base complex (SS) can be used as a suitable ionophore to prepare a sulfate-selective PVC-based membrane electrode. The use of oleic acid (OA) and hexadecyltrimethylammonium bromide (HTAB), as additives, and nitrobenzen (NB), dibutyl phthalate (DBP) and benzyl acetate (BA) as solvent mediators, were investigated. The best performance was observed with a membrane composition PVC: NB: SS: HTAB of 30%: 62%: 5%: 3% ratio. The resulting sensor works well over a wide concentration range (1.0 x 10(-2)-1.0 x 10(-6) M) with a Nernstian slope of -29.2 mV per decade of sulfate activity over a pH range 4.0-7.0. The limit of detection of the electrode is 5 x 10(-7) M. The proposed sensor shows excellent discriminating ability toward SO4(2-) ions with regard to many anions. It has a fast response time of about 15 s. The membrane electrode was used to the determination of zinc in zinc sulfate tablets. The sensor was also used as an indicator electrode in the potentiometric titration of SO4(2-) against barium ion.
authors.affiliation: Department of Chemistry, Tehran University, Tehran, Iran. Ganjali@khayam.ut.ac.ir
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Ganjali
authors.forename: Parviz
authors.initials: P
authors.lastname: Norouzi
authors.forename: Mahmood
authors.initials: M
authors.lastname: Gol-Mohammadi
authors.forename: Farhang
authors.initials: F
authors.lastname: Mizani
authors.forename: Tahereh
authors.initials: T
authors.lastname: Poursaberi
authors.forename: Masoud
authors.initials: M
authors.lastname: Salavati-Niasari
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Shamsipur
authors.forename: Morteza
authors.initials: M
authors.lastname: Hosseini
authors.forename: Mehran
authors.initials: M
authors.lastname: Javanbakht
mesh_terms: D017736:Ion-Selective Electrodes; D007476:Ionophores / Q000737:chemistry; D011143:Polyvinyl Chloride / Q000737:chemistry*; D011199:Potentiometry / Q000379:methods; D012545:Schiff Bases / Q000737:chemistry*; D013324:Strontium / Q000737:chemistry*; D013431:Sulfates / Q000032:analysis*; D015032:Zinc / Q000032:analysis / Q000737:chemistry; D019287:Zinc Sulfate / Q000737:chemistry
chemical_list: D007476:Ionophores; D012545:Schiff Bases; D013431:Sulfates; D019287:Zinc Sulfate; D011143:Polyvinyl Chloride; D015032:Zinc; D013324:Strontium