Ion-pairing agents in ion-selective electrodes for diquat, paraquat and 4,4-dipyridinium dications

Gordon Marnoch, RK Owusu, JDR Thomas

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

Phosphorus hexafluoride (PF6), anthraquinone-2-sulphonate (AS), octylsulphate (OS), picrate (PIC), dipicrylaminate (DPA), Diamine Green B (DGB), tetraphenylborate (TPB) and tetrakis-4-chlorophenylborate (T4CIPB) have been studied as possible ion-pairing agents for use in PVC-type liquid membrane ion-selective electrodes (ISEs) for diquat (DQT), paraquat (PQT) and 4,4′-dipyridinium (4,4′-DPy). Of these, only PF6, PIC, DGB, TPB and T4CIPB formed precipitates with DQT, PQT and 4,4′-DPy in aqueous solution, and only PF6, TPB and T4CIPB gave good electrodes; PF6-based electrodes were not selective.The analogy between ISE function and ion-pair extraction into an organic phase system is explored in detail. ISE characteristics, e.g., selectivity and minimum detectable activity of sample ion [a(min)] are quantitatively related to the sample ion membrane site association equilibrium and the lipophilicity of the ion pair formed.In agreement with the proposed theory, PIC is not sufficiently lipophilic to form the basis of a functional ISE for DQT, PQT or 4,4′-DPy. ISEs with T4CIPB as the membrane site show the best sensitivity for DQT (3 × 10–8M) or PQT (2 × 10–7M). The experimental selectivity coefficients for these ISEs in both instances are shown to be near to those calculated. Electrodes for 4,4′-DPy, studied as model systems, show an anomalously poor selectivity or sensitivity.
LanguageEnglish
Pages1347-1353
JournalThe Analyst
Volume112
Issue number10
DOIs
Publication statusPublished - 1987

Fingerprint

Diquat
Ion-Selective Electrodes
paraquat
Paraquat
electrode
Tetraphenylborate
Ions
ion
Electrodes
Diamines
Membranes
Anthraquinones
Liquid membranes
membrane
Polyvinyl Chloride
Polyvinyl chlorides
Phosphorus
Precipitates
sulfonate

Cite this

@article{dd0721fd1b8b40b89b5b7a88f1a5fd7f,
title = "Ion-pairing agents in ion-selective electrodes for diquat, paraquat and 4,4-dipyridinium dications",
abstract = "Phosphorus hexafluoride (PF6), anthraquinone-2-sulphonate (AS), octylsulphate (OS), picrate (PIC), dipicrylaminate (DPA), Diamine Green B (DGB), tetraphenylborate (TPB) and tetrakis-4-chlorophenylborate (T4CIPB) have been studied as possible ion-pairing agents for use in PVC-type liquid membrane ion-selective electrodes (ISEs) for diquat (DQT), paraquat (PQT) and 4,4′-dipyridinium (4,4′-DPy). Of these, only PF6, PIC, DGB, TPB and T4CIPB formed precipitates with DQT, PQT and 4,4′-DPy in aqueous solution, and only PF6, TPB and T4CIPB gave good electrodes; PF6-based electrodes were not selective.The analogy between ISE function and ion-pair extraction into an organic phase system is explored in detail. ISE characteristics, e.g., selectivity and minimum detectable activity of sample ion [a(min)] are quantitatively related to the sample ion membrane site association equilibrium and the lipophilicity of the ion pair formed.In agreement with the proposed theory, PIC is not sufficiently lipophilic to form the basis of a functional ISE for DQT, PQT or 4,4′-DPy. ISEs with T4CIPB as the membrane site show the best sensitivity for DQT (3 × 10–8M) or PQT (2 × 10–7M). The experimental selectivity coefficients for these ISEs in both instances are shown to be near to those calculated. Electrodes for 4,4′-DPy, studied as model systems, show an anomalously poor selectivity or sensitivity.",
author = "Gordon Marnoch and RK Owusu and JDR Thomas",
year = "1987",
doi = "10.1039/AN9871201347",
language = "English",
volume = "112",
pages = "1347--1353",
journal = "ANALYST",
issn = "0003-2654",
publisher = "Royal Society of Chemistry",
number = "10",

}

Ion-pairing agents in ion-selective electrodes for diquat, paraquat and 4,4-dipyridinium dications. / Marnoch, Gordon; Owusu, RK; Thomas, JDR.

In: The Analyst, Vol. 112, No. 10, 1987, p. 1347-1353.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Ion-pairing agents in ion-selective electrodes for diquat, paraquat and 4,4-dipyridinium dications

AU - Marnoch, Gordon

AU - Owusu, RK

AU - Thomas, JDR

PY - 1987

Y1 - 1987

N2 - Phosphorus hexafluoride (PF6), anthraquinone-2-sulphonate (AS), octylsulphate (OS), picrate (PIC), dipicrylaminate (DPA), Diamine Green B (DGB), tetraphenylborate (TPB) and tetrakis-4-chlorophenylborate (T4CIPB) have been studied as possible ion-pairing agents for use in PVC-type liquid membrane ion-selective electrodes (ISEs) for diquat (DQT), paraquat (PQT) and 4,4′-dipyridinium (4,4′-DPy). Of these, only PF6, PIC, DGB, TPB and T4CIPB formed precipitates with DQT, PQT and 4,4′-DPy in aqueous solution, and only PF6, TPB and T4CIPB gave good electrodes; PF6-based electrodes were not selective.The analogy between ISE function and ion-pair extraction into an organic phase system is explored in detail. ISE characteristics, e.g., selectivity and minimum detectable activity of sample ion [a(min)] are quantitatively related to the sample ion membrane site association equilibrium and the lipophilicity of the ion pair formed.In agreement with the proposed theory, PIC is not sufficiently lipophilic to form the basis of a functional ISE for DQT, PQT or 4,4′-DPy. ISEs with T4CIPB as the membrane site show the best sensitivity for DQT (3 × 10–8M) or PQT (2 × 10–7M). The experimental selectivity coefficients for these ISEs in both instances are shown to be near to those calculated. Electrodes for 4,4′-DPy, studied as model systems, show an anomalously poor selectivity or sensitivity.

AB - Phosphorus hexafluoride (PF6), anthraquinone-2-sulphonate (AS), octylsulphate (OS), picrate (PIC), dipicrylaminate (DPA), Diamine Green B (DGB), tetraphenylborate (TPB) and tetrakis-4-chlorophenylborate (T4CIPB) have been studied as possible ion-pairing agents for use in PVC-type liquid membrane ion-selective electrodes (ISEs) for diquat (DQT), paraquat (PQT) and 4,4′-dipyridinium (4,4′-DPy). Of these, only PF6, PIC, DGB, TPB and T4CIPB formed precipitates with DQT, PQT and 4,4′-DPy in aqueous solution, and only PF6, TPB and T4CIPB gave good electrodes; PF6-based electrodes were not selective.The analogy between ISE function and ion-pair extraction into an organic phase system is explored in detail. ISE characteristics, e.g., selectivity and minimum detectable activity of sample ion [a(min)] are quantitatively related to the sample ion membrane site association equilibrium and the lipophilicity of the ion pair formed.In agreement with the proposed theory, PIC is not sufficiently lipophilic to form the basis of a functional ISE for DQT, PQT or 4,4′-DPy. ISEs with T4CIPB as the membrane site show the best sensitivity for DQT (3 × 10–8M) or PQT (2 × 10–7M). The experimental selectivity coefficients for these ISEs in both instances are shown to be near to those calculated. Electrodes for 4,4′-DPy, studied as model systems, show an anomalously poor selectivity or sensitivity.

U2 - 10.1039/AN9871201347

DO - 10.1039/AN9871201347

M3 - Article

VL - 112

SP - 1347

EP - 1353

JO - ANALYST

T2 - ANALYST

JF - ANALYST

SN - 0003-2654

IS - 10

ER -