Determination of complex formation constants of 18 neutral alkali and alkaline earth metal ionophores in poly(vinyl chloride) sensing membranes plasticized with bis(2-ethylhexyl)sebacate and o-nitrophenyloctylether

Qin, Yu; Mi, Yanming; Bakker, Eric

doi:10.1016/s0003-2670(00)01038-2

Cited by 130 publications

(171 citation statements)

References 56 publications

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“…Similarly, the value determined earlier with the segmented sandwich membrane technique for DOS/PVC membranes with VIII (log β = 9.22) is lower by about two orders of magnitude than for the analogous o-NPOE/PVC membranes used here. These results are in line with previous observations on a series of other ionophores [49].…”

Section: Resultssupporting

confidence: 93%

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

Szigeti

Malon

Vigassy

et al. 2006

Analytica Chimica Acta

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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.

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Section: Resultssupporting

confidence: 93%

“…For membranes with ionophores VII-X, the values of log β are similar (for o-NPOE/PVC membranes >10 10 ). They are of the same order as those found with the best ionophores for monovalent ions [49] and also similar to that determined recently with a tripodal N-acylthiourea ionophore (10 11.7 ) [15].…”

Section: Resultssupporting

confidence: 89%

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

Szigeti

Malon

Vigassy

et al. 2006

Analytica Chimica Acta

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“…In the more polar membrane matrix (PVC/o-NPOE), the logβ values for all four ionophores and each anion tested were found to be higher then those obtained for the less polar matrix (PVC/DOS) (see Figure 7). A similar plasticizer effect was reported previously for cation binding by cation-selective ionophores [32]. The highest differences are observed for the complexes of Al[t-BTPP], and Zr[t-BTPP], with fluoride (Δlogβ >1), while the differences in logβ for the other complexes are less pronounced (< 0.5).…”

Section: When Comparing the Anion Complexation Constants Of Al[t-btppsupporting

confidence: 84%

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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“…Here, potassium ionophore I exhibits the highest binding constant compared to sodium ionophore X and lithium ionophore VIII and thus the K + titration curve appears the sharpest. 33 All titration curves agree very well with theory (see Supporting Information).…”

Section: Acs Sensorssupporting

confidence: 76%

“…The logarithmic effective binding constants (logβ) of potassium ionophore I in the nanospheres has recently been determined as 6.1 ± 0.1, 23 about 4 orders of magnitude lower than those reported earlier in PVC-DOS membrane (logβ = 10.1 ± 0.2). 33 The corresponding value in CH 2 Cl 2 was here experimentally determined as 10.2 ± 0.1 which is practically …”

Section: Acs Sensorsmentioning

confidence: 68%

Ionophore-Based Titrimetric Detection of Alkali Metal Ions in Serum

et al. 2017

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While the titrimetric assay is one of the most precise analytical techniques available, only a limited list of complexometric chelators is available, as many otherwise promising reagents are not water-soluble. Recent work demonstrated successful titrimetry with ion-exchanging polymeric nanospheres containing hydrophobic complexing agents, socalled ionophores, opening an exciting avenue in this field. However, this method was limited to ionophores of very high affinity to the analyte and exhibited a relatively limited titration capacity. To overcome these two limitations, we report here on solvent based titration reagents. This heterogeneous titration principle is based on the dissolution of all hydrophobic recognition components in a solvent such as dichloromethane (CH 2 Cl 2 ) where the ionophores are shown to maintain a high affinity to the target ions. HSV (hue, saturation, value) analysis of the images captured with a digital camera provides a convenient and inexpensive way to determine the end point. This approach is combined with an automated titration setup. The titrations of the alkali metals K + , Na + , and Li + in aqueous solution are successfully demonstrated. The potassium concentration in human serum without pretreatment was precisely and accurately determined as 4.38 mM ± 0.10 mM (automated titration), which compares favorably with atomic emission spectroscopy (4.47 mM ± 0.20 mM).

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Determination of complex formation constants of 18 neutral alkali and alkaline earth metal ionophores in poly(vinyl chloride) sensing membranes plasticized with bis(2-ethylhexyl)sebacate and o-nitrophenyloctylether

Cited by 130 publications

References 56 publications

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

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

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

Ionophore-Based Titrimetric Detection of Alkali Metal Ions in Serum

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