Influence of phosphate buffer and proteins on the potentiometric response of a polymeric membrane-based solid-contact Pb(II) ion-selective electrode

A1 Journal article (refereed)


Internal Authors/Editors


Publication Details

List of Authors: Narender Kumar Joon, Ning He, Michal Wagner, Marité Cárdenas, Johan Bobacka, Grzegorz Lisak
Publisher: PERGAMON-ELSEVIER SCIENCE LTD
Publication year: 2017
Journal: Electrochimica Acta
Journal acronym: ELECTROCHIM ACTA
Volume number: 252
Start page: 490
End page: 497
eISSN: 1873-3859


Abstract

In this work, the influence of phosphate buffer and proteins on the potentiometric response of a polymeric membrane-based solid-contact Pb2+-selective electrode (Pb2+-ISE) was studied. The effects of bovine serum albumin (BSA) adsorption at the surface of the ion-selective membrane combined with electrode conditioning in phosphate-buffered saline (PBS) solution was elucidated by potentiometry and electrochemical impedance spectroscopy. The adsorbed BSA at the surface of the Pb2+-ISE slightly lowered the detection limit but did not influence the selectivity of the Pb2+-ISE towards the interfering ions studied (Cu2+, Cd2+). Conditioning of the Pb2+-ISE in 0.01 mol dm–3 PBS resulted in a super-Nernstian response which was related to fixation/extraction of Pb2+ in the ion-selective membrane via precipitation of Pb3(PO4)2 by PO43– anions present in PBS. By conditioning of the Pb2+-ISE in 0.01 mol dm–3 PBS + 1 mg/ml BSA it was possible to extend the linear response range of the Pb2+-ISE towards lower analyte concentrations. The utilization of this conditioning procedure was validated by determination of Pb2+ concentrations down to ca 20 ppb in aqueous samples by Pb2+-ISEs and by comparing the results with those obtained by ICP-MS.


Keywords

Electrochemistry, phosphate buffer, Potentiometric sensors, Protein adsorption

Last updated on 2019-18-08 at 06:45