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

A1 Originalartikel i en vetenskaplig tidskrift (referentgranskad)


Interna författare/redaktörer


Publikationens författare: Narender Kumar Joon, Ning He, Michal Wagner, Marité Cárdenas, Johan Bobacka, Grzegorz Lisak
Förläggare: PERGAMON-ELSEVIER SCIENCE LTD
Publiceringsår: 2017
Tidskrift: Electrochimica Acta
Tidskriftsakronym: ELECTROCHIM ACTA
Volym: 252
Artikelns första sida, sidnummer: 490
Artikelns sista sida, sidnummer: 497
eISSN: 1873-3859


Abstrakt

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.


Nyckelord

Electrochemistry, phosphate buffer, Potentiometric sensors, Protein adsorption

Senast uppdaterad 2020-28-02 vid 04:16