title: Continuous flow analysis of iron in zinc electrowinning electrolyte using an iron chalcogenide glass ion-selective electrode Part I. Synthetic media.
abstract: It is shown that the iron(III) chalcogenide glass membrane ion-selective electrode (ISE) can be calibrated in continuous flow analysis (CFA) using acidified iron(III) nitrate standards, yielding a 60+/-3 mV per decade change in activity of Fe(3+) response in the range 10(-7)-10(-2) M total iron(III). Extended ageing of the iron(III) ISE in 2 M zinc(II) sulphate did not alter the potentiometric response characteristics of the electrode. Furthermore, electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy in the presence and absence of zinc(II) sulphate failed to detect a zinc(II) interference on the iron(III) ISE. CFA/ISE determined activities of Fe(3+) in synthetic zinc electrolyte containing 2x10(-3)-2x10(-1) M total iron(III) yielded results falling within +/-0.2logaFe(3+) unit of the corresponding iron speciation data calculated using the minteqa2 program.
authors.affiliation: School of Applied Chemistry, Curtin University of Technology, GPO Box U 1987, Perth, Western Australia 6845, Australia.
authors.forename: Roland
authors.initials: R
authors.lastname: De Marco
authors.forename: Bobby
authors.initials: B
authors.lastname: Pejcic
authors.forename: Mitch
authors.initials: M
authors.lastname: Loan
authors.forename: Matthew
authors.initials: M
authors.lastname: Wilcox