Carrier-Based Ion-Selective Electrodes and Bulk Optodes. 1. General Characteristics

Bakker, Eric; Bühlmann, Philippe; Pretsch, Ernö

doi:10.1021/cr940394a

Cited by 2,291 publications

(2,006 citation statements)

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“…Anion-selective membranes doped with ionophores that function as charged carriers requires lipophilic anionic site additives (B, in Table 1), while cationic additives (T, in Table 1) are necessary in the case of ionophores that function as neutral carriers. It has been reported that Zr(IV)-porphyrins and other metalloporphyrins are able to function as both charged and neutral carriers [22][23][24][25]. To determine whether this so called "mixedmode" mechanism also exists in the case of new ionophores reported hererin, a series of membranes containing 10 mol% of cationic or anionic additives (relative to ionophore) were prepared (see Table 1).…”

Section: Determination Of Working Mechanism For Ionophores Testedmentioning

confidence: 99%

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Polymeric membrane electrodes with improved fluoride selectivity and lifetime based on Zr(IV)- and Al(III)-tetraphenylporphyrin derivatives

Pietrzak

Meyerhoff

Malinowska

2007

Analytica Chimica Acta

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Novel aluminum(III)-and zirconium(IV)-tetraphenylporhyrin (TPP) derivatives are examined as fluoride selective ionophores for preparing polymer membrane-based ion-selective electrodes (ISEs). The influence of t-butyl-or dichloro-phenyl ring substituents as well as the nature of the metal ion center (Al(III) vs. Zr(IV)) on the anion complexation constants of TPP derivative ionophores are reported. The anion binding stability constants of the ionophores are characterized by the so-called "sandwich membrane" method. All of the metalloporphyrins examined form their strongest anion complexes with fluoride. The influence of plasticizer as well as the type of lipophilic ionic site additive and their amounts in the sensing membrane are discussed. It is shown that membrane electrodes formulated with the metalloporphyrin derivatives and appropriate anionic or cationic additives exhibit enhanced potentiometric response toward fluoride over all other anions tested. Since selectivity toward fluoride is enhanced in the presence of both anionic and cationic additives, the metalloporphyrins can function as either charged or neutral carriers within the organic membrane phase. In contrast to previously reported fluoride-selective polymeric membrane electrodes based on metalloporphyrins, nernstian or near-nernstian (−51.2 to −60.1 mV decade −1 ) as well as rapid (t < 80s) and fully reversible potentiometric fluoride responses are observed. Moreover, use of aluminum (III)-t-butyltetraphenylporphyrin as the ionophore provides fluoride sensors with prolonged (7 months) functional life-time.

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Section: Determination Of Working Mechanism For Ionophores Testedmentioning

confidence: 99%

“…It is well established that the formation constants of ion-ionophore complexes in the organic membrane phase are the critical parameter that influence the observed selectivity of polymeric membrane ISEs [23]. Most classical methods useful for determining ion-ionophore complex stability constants (e.g., NMR, etc.)…”

Section: Stability Constantsmentioning

confidence: 99%

Polymeric membrane electrodes with improved fluoride selectivity and lifetime based on Zr(IV)- and Al(III)-tetraphenylporphyrin derivatives

Pietrzak

Meyerhoff

Malinowska

2007

Analytica Chimica Acta

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“…DOS and o-NPOE are representatives of low and high dielectric constant plasticizers with dielectric constants of 4.8 and 24, respectively, in their pure forms. o-NPOE plasticized PVC membranes have much higher polarities [24]. It can be seen in Table 3 that electrodes using o-NPOE as plasticizer show the best response.…”

Section: Characteristics Of the Ionophore-based Ag + -Isesmentioning

confidence: 98%

Synthesis and characterization of monoazathiacrown ethers as ionophores for polymeric membrane silver-selective electrodes

Zhang

Ding

Yin

et al. 2010

Talanta

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“…1 Ion selective electrodes (ISEs) have been already widely used in a variety of fields such as clinical analysis, 2 process control 3 and environmental monitoring. 4 Ion selective membranes are typically composed of plasticized polymers, ion exchange salts, and one or more ionophores.…”

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confidence: 99%

Simple, Robust, and Plasticizer-Free Iodide-Selective Sensor Based on Copolymerized Triazole-Based Ionic Liquid

Mendecki

Chen

Callan³

et al. 2016

Anal. Chem.

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Novel solid contact iodide selective electrodes based on covalently attached 1,2,3 triazole ionic liquid (IL) were prepared and investigated in this study. Triazole-based IL moieties were synthesized using click chemistry and were further copolymerized with lauryl methacrylate via a simple one step free radical polymerization to produce a "self-plasticized" copolymer. The mechanical properties of the copolymer are suitable for the fabrication of plasticizer-free ion-selective membrane electrodes. We demonstrate that covalently attached IL moieties provide adequate functionality to the ion selective membrane thus achieving a very simple, one component sensing membrane. We also demonstrate the presence of iodide as the counter-ion in the triazole moiety has direct influence on membrane's functionality. Potentiometric experiments revealed that each electrode displays high selectivity towards iodide anions over a number of inorganic anions. Moreover the inherent presence of the iodide in the membrane reduces the need for conditioning. The non-conditioned electrodes show strikingly similar response characteristics compared to the conditioned ones. The electrodes exhibited a near Nernstian behavior with a slope of -56.1 mV per decade across large concentration range with lower detection limits found at approximately 6.3x10 -8 M or 8 ppb . These all-solid state sensors were utilized for the selective potentiometric determination of iodide ions in artificial urine samples in the nanomolar concentration range.Potentiometric chemical sensors, with primary responses based on extraction and molecular recognition processes are a wellstudied and understood class of sensing devices. 1 Ion selective electrodes (ISEs) have been already widely used in a variety of fields such as clinical analysis, 2 process control 3 and environmental monitoring. 4 Ion selective membranes are typically composed of plasticized polymers, ion exchange salts, and one or more ionophores. Each constituent plays a specific role in the proper functioning of these membrane based ISEs. 5 Spontaneous and non-specific extraction of analyte ions from the sample into the membrane bulk is primarily suppressed due to the highly hydrophobic nature of the polymer backbone. Ideally, polymer matrix should provide a homogenous medium in which all active components can move freely. This strongly resembles the composition of liquid membrane electrodes since their sensing components were simply dissolved in an organic medium. However, the performance of polymer-based membranes can be drastically reduced if such sensors are used for the measurements of ions within more lipophilic environments in biological samples including undiluted whole blood. The cross contamination of chemical sensors coupled with leaching of the sensing components from the ion selective membrane into the sample fundamentally limited the applications of ISEs as a robust analytical tool for long-term trace level analysis. 6 Over the years, a number of approaches have been developed to minim...

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Carrier-Based Ion-Selective Electrodes and Bulk Optodes. 1. General Characteristics

Cited by 2,291 publications

References 308 publications

Polymeric membrane electrodes with improved fluoride selectivity and lifetime based on Zr(IV)- and Al(III)-tetraphenylporphyrin derivatives

Polymeric membrane electrodes with improved fluoride selectivity and lifetime based on Zr(IV)- and Al(III)-tetraphenylporphyrin derivatives

Synthesis and characterization of monoazathiacrown ethers as ionophores for polymeric membrane silver-selective electrodes

Simple, Robust, and Plasticizer-Free Iodide-Selective Sensor Based on Copolymerized Triazole-Based Ionic Liquid

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