title: Calibration of the Hg chalcogenide glass membrane ion-selective electrode in seawater media.
abstract: It is shown that a chalcogenide glass mercury(II) ion-selective electrode (ISE) can be calibrated in chloride-free unbuffered and saline buffered standards, displaying near-Nernstian response over 19 orders of magnitude (i.e. 10(-20) to 10(-1) M Hg(2+)). Extended ageing of the ISE in seawater induced a memory effect, causing the electrode to respond in a sub-Nernstian fashion. Electrochemical impedance spectroscopy (EIS) demonstrated that the response of the Hg(II) ISE is underpinned by a charge transfer process, and seawater matrix effects are due to electrode passivation. It is shown that standard addition ISE potentiometry may compensate for interferences caused by the seawater matrix.
authors.affiliation: School of Applied Chemistry, Curtin University of Technology, GPO Box U 1987, Perth, WA 6845, Australia.
authors.forename: R
authors.initials: R
authors.lastname: De Marco
authors.forename: J
authors.initials: J
authors.lastname: Shackleton