TY - JOUR

T1 - Potentiometric performance and interfacial kinetics of neutral lonophore based ISE membranes in interfering ion solutions before and after contact with primary ions

AU - Mikhelson, Konstantin N.

AU - Bobacka, Johan

AU - Lewenstam, Andrzej

AU - Ivaska, Ari

PY - 2001

Y1 - 2001

N2 - The potentiometric response and the electrochemical impedance spectra of thin PVC based membranes selective to Ca2+ and to Na+ were studied before and after first contact with respective primary ions. The membranes included potassium tetrakis(p-Cl-phenyl) borate, thus being initially in potassium form. Nearly Nernstian potentiometric responses were obtained in interfering electrolytes before the contact with primary ions, while after the first contact the slope of potentiometric curves decreased drastically. However, the impedance spectra were similar regardless of prior conditioning of the membranes, and no evidence for a hindrance towards charge transfer processes was observed. The results suggest that the membrane/solution interface reactions are reversible both for the primary and the interfering ions, and the contamination of the solutions with primary ions is the only reason for the lack of Nernstian response in interfering electrolytes.

AB - The potentiometric response and the electrochemical impedance spectra of thin PVC based membranes selective to Ca2+ and to Na+ were studied before and after first contact with respective primary ions. The membranes included potassium tetrakis(p-Cl-phenyl) borate, thus being initially in potassium form. Nearly Nernstian potentiometric responses were obtained in interfering electrolytes before the contact with primary ions, while after the first contact the slope of potentiometric curves decreased drastically. However, the impedance spectra were similar regardless of prior conditioning of the membranes, and no evidence for a hindrance towards charge transfer processes was observed. The results suggest that the membrane/solution interface reactions are reversible both for the primary and the interfering ions, and the contamination of the solutions with primary ions is the only reason for the lack of Nernstian response in interfering electrolytes.

KW - Ca ions

KW - Impedance spectra

KW - Interfacial kinetics

KW - Na ions

KW - Neutral ionophone based ISE membranes

KW - Potentiometric response

UR - http://www.scopus.com/inward/record.url?scp=85078684557&partnerID=8YFLogxK

U2 - 10.1002/1521-4109(200106)13:10<876::aid-elan876>3.0.co;2-%23

DO - 10.1002/1521-4109(200106)13:10<876::aid-elan876>3.0.co;2-%23

M3 - Article

AN - SCOPUS:85078684557

VL - 13

SP - 876

EP - 881

JO - Electroanalysis

JF - Electroanalysis

SN - 1040-0397

IS - 10

ER -