Determination of Unbiased Selectivity Coefficients of Neutral Carrier-Based Cation-Selective Electrodes

Bakker, Eric

doi:10.1021/ac960891m

Cited by 362 publications

(356 citation statements)

References 24 publications

Supporting

Mentioning

335

Contrasting

Unclassified

Order By: Relevance

“…This process leads to a bias in the detection limit and in the calculated selectivity coefficients that can amount to many orders of magnitude. 25,27,28 The selectivity bias can be quite easily eliminated by various means, including the use of ion buffers in the sample, 29 membranes that have not been exposed to the most preferred ions before characterization, 30 and membranes that exhibit a siphoning effect in direction of the inner solution. 31 Selectivity coefficients obtained with any of these methodologies often reflect a much better selectivity than with traditional, biased protocols.…”

Section: Detection Limitmentioning

confidence: 99%

Modern directions for potentiometric sensors

Bakker¹,

Chumbimuni‐Torres²

2008

J. Braz. Chem. Soc.

Self Cite

View full text Add to dashboard Cite

Este artigo apresenta uma revisão dos mais recentes progressos dos eletrodos íons-seletivos de membrana polimérica. É discutida uma essência curta da teoria básica, enfatizando como a força eletromotriz pode ser usada para calcular as constantes de ligação do ionóforo, e como a seletividade e o limite de detecção estão relacionados aos processos de membrana mais importantes. Os recentes progressos na diminuição dos limites de detecção dos ISEs são descritos, incluindo recentes tentativas no desenvolvimento de ISEs de contato sólido, e inovações na detecção de quantidades ultra-pequenas de íons em baixas concentrações. Esses progressos têm alçado o caminho para usar sensores potenciométricos em bioanálise com afinidade ultra-sensível junto com nanopartículas usadas como marcadores. Os resultados recentes estabelecem que a potenciometria compara-se favoravelmente com a análise de redissolução eletroquímica. Outros novos progressos com os eletrodos de íon-seletivo são também descritos, incluindo o conceito de potenciometria de calibração interna, coulometria de corrente controlada, cronopotenciometria pulsada, e titulação rápida localizada com membranas íon-seletivas para desenhar sensores de detecção direta da acidez total sem perturbação da amostra. Estes progressos têm aberto um amplo campo para novos desenvolvimentos e aplicações nesta área. This paper gives an overview of the newest developments of polymeric membrane ion-selective electrodes. A short essence of the underlying theory is given, emphasizing how the electromotive force may be used to assess binding constants of the ionophore, and how the selectivity and detection limit are related to the basic membrane processes. The recent developments in lowering the detection limits of ISEs are described, including recent approaches of developing all solid state ISEs, and breakthroughs in detecting ultra-small quantities of ions at low concentrations. These developments have paved the way to use potentiometric sensors as in ultra-sensitive affinity bioanalysis in conjunction with nanoparticle labels. Recent results establish that potentiometry compares favorably to electrochemical stripping analysis. Other new developments with ion-selective electrodes are also described, including the concept of backside calibration potentiometry, controlled current coulometry, pulsed chronopotentiometry, and localized flash titration with ion-selective membranes to design sensors for the direct detection of total acidity without net sample perturbation. These developments have further opened the field for exciting new possibilities and applications.

show abstract

Section: Detection Limitmentioning

confidence: 99%

Modern directions for potentiometric sensors

Bakker¹,

Chumbimuni‐Torres²

2008

J. Braz. Chem. Soc.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Unbiased selectivity coefficients can be obtained either by measuring the calibration curves for discriminated ions before the first contact of the membrane with the primary ion [27] or by using appropriate inner solutions [28]. The response slopes for the interfering ions must be recorded since close to theoretical values confirm that selectivity coefficients are not biased [29].…”

Section: Introductionmentioning

confidence: 99%

Novel potentiometric and optical silver ion-selective sensors with subnanomolar detection limits

Szigeti

Malon

Vigassy

et al. 2006

Analytica Chimica Acta

Self Cite

View full text Add to dashboard Cite

Ten Ag + -selective ionophores have been characterized in terms of their potentiometric selectivities and complex formation constants in solvent polymeric membranes. The compounds with π-coordination show much weaker interactions than those with thioether or thiocarbamate groups as the coordinating sites. Long-term studies with the best ionophores show that the lower detection limit of the best Ag + sensors can be maintained in the subnanomolar range for at least one month. The best ionophores have also been characterized in fluorescent microspheres. The so far best lower detection limits of 3× 10 −11 M (potentiometrically) and 2 × 10 −11 M Ag + (optically) are found with bridged thiacalixarenes.

show abstract

“…The present results for K ij « 1 document that selectivity coefficients near the hypothetical equilibrium values can be realized only at the highest sample activities. At lower activities, the selectivity behavior is usually far from the thermodynamically controlled domain, unless the studied ISE membrane has initially not been prepared with the respective interfering ion j instead of the primary ion i [36]. This holds at least for relatively short measurements.…”

Section: Resultsmentioning

confidence: 99%

Theory and computer simulation of the time-dependent selectivity behavior of polymeric membrane ion-selective electrodes

Morf

Pretsch

Rooij

2008

Journal of Electroanalytical Chemistry

View full text Add to dashboard Cite

A theoretical treatment of the time-dependent potential response of ion-selective electrodes to sample solutions containing primary and interfering ions is presented. The theory accounts for the influence of ion fluxes in the electrode membrane and the contacting aqueous sample layer and describes the variations in the apparent selectivity behavior as a function of the measuring time. The applicability of the theory is demonstrated by comparing predicted response curves with results of virtual experiments based on computer simulation. A close and convincing agreement was achieved for a large series of different examples, which confirms that the new theory can be successfully applied for general cases.

show abstract

Determination of Unbiased Selectivity Coefficients of Neutral Carrier-Based Cation-Selective Electrodes

Cited by 362 publications

References 24 publications

Modern directions for potentiometric sensors

Modern directions for potentiometric sensors

Novel potentiometric and optical silver ion-selective sensors with subnanomolar detection limits

Theory and computer simulation of the time-dependent selectivity behavior of polymeric membrane ion-selective electrodes

Contact Info

Product

Resources

About