1201
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Malinowska E, Gawart L, Parzuchowski P, Rokicki G, Brzózka Z. Novel approach of immobilization of calix[4]arene type ionophore in ‘self-plasticized’ polymeric membrane. Anal Chim Acta 2000. [DOI: 10.1016/s0003-2670(00)00999-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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1202
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New longwave absorbing chromogenic calix[4]arene for calcium determination in aqueous environment. Anal Chim Acta 2000. [DOI: 10.1016/s0003-2670(00)01049-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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1203
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Qin Y, Mi Y, Bakker E. 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. Anal Chim Acta 2000. [DOI: 10.1016/s0003-2670(00)01038-2] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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1204
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Oh KS, Lee CW, Choi HS, Lee SJ, Kim KS. Origin of the high affinity and selectivity of novel receptors for NH4+ over K+: charged hydrogen bonds vs cation-pi interaction. Org Lett 2000; 2:2679-81. [PMID: 10990426 DOI: 10.1021/ol000159g] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[structure: see text]Given the recent report of a novel pyrazole receptor exhibiting a high selectivity for NH4+ over K+, it would be interesting to investigate the origin of this selectivity and affinity so that better receptors could be designed. On the basis of extensive theoretical studies, we conclude that the origin arises from a subtle interplay of charged H-bonds and cation-pi interactions. The approach employed herein would be very useful in the rational design of novel functional molecular systems.
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Affiliation(s)
- K S Oh
- National Creative Research Initiative Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, Namgu, Korea
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1205
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Shamsipur M, Rouhani S, Mohajeri A, Ganjali MR, Rashidi-Ranjbar P. A bromide ion-selective polymeric membrane electrode based on a benzo-derivative xanthenium bromide salt. Anal Chim Acta 2000. [DOI: 10.1016/s0003-2670(00)00954-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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1206
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1207
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Improved detection limits and unbiased selectivity coefficients obtained by using ion-exchange resins in the inner reference solution of ion-selective polymeric membrane electrodes. Anal Chem 2000; 72:3236-40. [PMID: 10939393 DOI: 10.1021/ac000155p] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
By using a high concentration of an interfering ion and a low one of the primary ion in the inner reference solution of polymeric membrane ion-selective electrodes (ISEs), the lower detection limit may be improved and unbiased thermodynamic selectivity coefficients may be obtained. To this purpose, a cation-exchange resin is used here to keep the low concentration of the primary cation constant. Different compositions of the internal solution are required for obtaining optimal lower detection limits and unbiased selectivity coefficients. All ISEs studied here, i.e., for K+, Ca2+, and NH4+, based on valinomycin, ETH 5234, and nonactin/monactin, respectively, show improved lower detection limits in the range of 10(-7.6) (NH4+) to 10(-8.8) M (Ca2+). Nernstian responses and, therefore, unbiased selectivity coefficients are obtained with the K+-ISE for the discriminated ions, Na+, Mg2+, and Ca2+.
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1208
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1209
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Bakker E, Meyerhoff ME. Ionophore-based membrane electrodes: new analytical concepts and non-classical response mechanisms. Anal Chim Acta 2000. [DOI: 10.1016/s0003-2670(00)00883-7] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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1210
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Shamsipur M, Madrakian T. Competitive lithium-7 NMR study of the complexation of some alkaline earth and transition metal ions with 18-crown-6 in acetonitrile and its 50:50 mixtures with nitrobenzene and nitroethane. Polyhedron 2000. [DOI: 10.1016/s0277-5387(00)00417-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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1211
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van der Veen NJ, Flink S, Deij MA, Egberink RJM, van Veggel FCJM, Reinhoudt DN. Monolayer of a Na+-Selective Fluoroionophore on Glass: Connecting the Fields of Monolayers and Optical Detection of Metal Ions. J Am Chem Soc 2000. [DOI: 10.1021/ja000713h] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Niels J. van der Veen
- Department of Supramolecular Chemistry and Technology MESA+ Research Institute, University of Twente P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Simon Flink
- Department of Supramolecular Chemistry and Technology MESA+ Research Institute, University of Twente P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Menno A. Deij
- Department of Supramolecular Chemistry and Technology MESA+ Research Institute, University of Twente P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Richard J. M. Egberink
- Department of Supramolecular Chemistry and Technology MESA+ Research Institute, University of Twente P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Frank C. J. M. van Veggel
- Department of Supramolecular Chemistry and Technology MESA+ Research Institute, University of Twente P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - David N. Reinhoudt
- Department of Supramolecular Chemistry and Technology MESA+ Research Institute, University of Twente P.O. Box 217, 7500 AE, Enschede, The Netherlands
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1212
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Abstract
A PVC membrane sensor for cerium(III) ions based on 1,3,5-trithiane as membrane carrier was prepared. The sensor has a linear dynamic range of 1.0 x 10(-1)-5.0 x 10(-5) M, with a Nernstian slope of 19.4+/-0.4 mV decade(-1), and a detection limit 3.0 x 10(-5) M. It has a fast response time of < 15 s and can be used for at least 5 months without any considerable divergence in potentials. The proposed sensor revealed comparatively good selectivities with respect to alkali, alkaline earth, and some transition and heavy metal ions and could be used in a pH range of 5.0-8.0. It was used as an indicator electrode in potentiometric titration of oxalate and fluoride ions and in determination of F- ion in some mouth wash preparations.
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1213
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Molecular design of crown ethers. 19.(1) synthesis of novel disulfide- and diselenide-bridged Bis(benzo-12-crown-4)s and their Ag(+)-selective electrode properties. J Org Chem 2000; 65:2870-4. [PMID: 10814172 DOI: 10.1021/jo991142i] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Two novel heteroatom-bridged bis(benzo-12-crown-4 ether)s, i.e., bis(2-nitro-4,5-(1,4,7,10-tetraoxadecamethylene)phenyl) disulfide (4) and diselenide (5), have been synthesized and characterized by elemental analysis and mass, IR, UV, and (1)H NMR spectroscopy. An X-ray crystallographic structure was obtained for 4. Ion-selective electrodes (ISE) for Ag(+), containing 4 and 5 in PVC membrane as neutral carriers, were prepared, and their selectivity coefficients for Ag(+) () were determined against other heavy metal ions, alkali and alkaline-earth metal ions, and ammonium ion using the matched potential method. These ISEs showed excellent Ag(+) selectivities, log </= -4.0, against most of the interfering cations examined, except for Hg(+) (log >/= -1.2). These values are comparable to those reported for the representative Ag(+)-selective thioethers 6 and 7, revealing that both disulfide and diselenide functionalities in 4 and 5 are equally effective Ag(+)-selective binding sites as the 1,7-dithia-4-oxa functionality in 6 and 7, irrespective of the different atom type and relative position of the sulfur/selenium donors in the ligands. Also discussed are the steric and electronic effects of the nitro groups in 4 and 5 on the Nernstian slopes obtained with the 4- and 5-based ISEs.
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1214
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Design and synthesis of a more highly selective ammonium ionophore than nonactin and its application as an ion-sensing component for an ion-selective electrode. Anal Chem 2000; 72:2200-5. [PMID: 10845363 DOI: 10.1021/ac9911241] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A novel ammonium ionophore, which exhibits superior NH4+ selectivity compared with that of the natural antibiotic nonactin, was successfully designed and synthesized based on a 19-membered crown compound (TD19C6) having three decalino subunits in the macrocyclic system. This bulky decalino subunit is effective for (1) increasing the structural rigidity of the cyclic compound, (2) introducing the "block-wall effect", which prevents forming a complex with a large ion, and (3) increasing the lipophilicity of the ionophore molecule. In the ammonium ionophore design, the first factor contributes to increasing the NH4+ selectivity relative to smaller ions such as Li+, Na+, or even the closest size, K+, and the second factor increases the NH4+ selectivity over larger ions such as Rb+ and Cs+. The X-ray structural analysis proved that TD19C6 forms a size-fit complexwith NH4+ in its crown ring cavity. As an application of this ionophore, an ion sensor (ion-selective electrode) was prepared, which exhibited NH4+ to K+ and Na+ selectivity of 10 and 3,000 times, respectively. This electrode showed a better performance compared to the electrode based on nonactin, which is the only ammonium ionophore presently used in practical applications.
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1215
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Shabanov AL, Khandar A, Mamedov CI, Babazade AM, Sultanzade SS. Highly sensitive ion-selective electrodes based on dithiacrown ethers for the determination of mercury in fish samples. JOURNAL OF ANALYTICAL CHEMISTRY 2000. [DOI: 10.1007/bf02757486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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1216
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Abstract
The lifetime of solvent polymeric ion-selective electrodes (ISEs) is limited by leaching of the membrane components into the sample solutions. In this article, leaching of charged ionophores is discussed. Because of the electroneutrality principle, the loss of the charged ionophore into the sample must be accompanied by parallel transport of an ion of the opposite charge sign into the sample or by ion exchange with a sample ion of the same charge sign. Because ionic sites of high lipophilicity are available, the loss of ionic sites is, in general, not a concern. Therefore, it is assumed here that the cotransported or ion-exchanging ions are primary or interfering ions forming complexes with the ionophore. A general theory that allows quantification of ionophore lipophilicities and a discussion of changes in the membrane composition and selectivity with time is presented. A high complex stability and high analyte concentrations diminish the rate of ionophore loss into the sample if a charged ionophore is coextracted from the membrane into the sample together with an analyte ion of opposite charge. On the other hand, if the charged ionophore has the same charge sign as the ion that it binds, a large binding constant and high analyte concentrations enhance ionophore leaching into the sample. The model is applied to interpret results for an electrically charged ionophore, for which selectivity changes as a function of the leaching time were observed and the lipophilicity was determined with potentiometric measurements. Using the lipophilicities of neutral ionophores, as described previously, and the lipophilicities of charged ionophores, as described here, a direct comparison of the expected leaching rates of charged and neutral ionophores has become possible.
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1217
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Cationic or anionic sites? Selectivity optimization of ion-selective electrodes based on charged ionophores. Anal Chem 2000; 72:1618-31. [PMID: 10763261 DOI: 10.1021/ac991167h] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The influence of ionic sites on the selectivities of ionophore-based ion-selective electrodes (ISEs) is described on the basis of a phase boundary potential model. The discussion presented here is significantly more general than previous ones. It is formulated for primary and interfering ions of any charges and it is valid for ISEs based on electrically charged or neutral ionophores. Furthermore, it also applies to membranes that contain more than one type of complex of the primary or interfering ion. It has been believed thus far that only ionic sites of the same charge sign as the primary ion improve the selectivities of ISEs based on charged ionophores. However, it is shown here that the charge sign of the ionic sites that give the highest potentiometric selectivities depends on the charge number of the primary and interfering ions and on the stoichiometry of their complexes with the ionophore. The validity of our model was confirmed experimentally with three ISEs based on different charged ionophores. ISEs based on lasalocid or 1-(N,N-dicyclohexylcarbamoyl)-2- (N,N-dioctadecylcarbamoyl)ethylphosphonic acid monomethyl ester (ETH 5639) as the ionophore responded selectively to Sr2+ or Mg2+, respectively, and discriminated well against other alkaline earth cations when their membranes contained anionic sites. These two electrodes are the first examples of ISEs based on charged ionophores for which maximum selectivities are obtained with membranes containing ionic sites with a charge sign opposite to that of the primary ion. On the other hand, the experimental F- selectivities of membranes based on oxo(5,10,15,20-tetraphenylporphyrinato)molybdenum-(V) improved gradually when the concentration of anionic sites was increased from 0 to 75 mol%. The selectivity-modifying influence of ionic sites for these three types of ISEs can be explained by considering the different stabilities of the 1:2 ion-ionophore complexes of the primary and of the interfering ions.
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1218
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Abstract
Selectivities of solvent polymeric membrane ion-selective electrodes (ISEs) are quantitatively related to equilibria at the interface between the sample and the electrode membrane. However, only correctly determined selectivity coefficients allow accurate predictions of ISE responses to real-world samples. Moreover, they are also required for the optimization of ionophore structures and membrane compositions. Best suited for such purposes are potentiometric selectivity coefficients as defined already in the 1960s. This paper briefly reviews the basic relationships and focuses on possible biases in the determination of selectivity coefficients. The traditional methods to determine selectivity coefficients (separate solution method, fixed interference method) are still the same as those originally proposed by IUPAC in 1976. However, several precautions are needed to obtain meaningful data. For example, errors arise when the response to a weakly interfering ion is also influenced by the primary ion leaching from the membrane. Wrong selectivity coefficients may be also obtained when the interfering agent is highly preferred and the electrode shows counterion interference. Recent advances show how such pitfalls can be avoided. A detailed recipe to determine correct potentiometric selectivity coefficients unaffected by such biases is presented.
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Affiliation(s)
- E Bakker
- Department of Chemistry, Aubum University, Alabama 36849, USA
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1219
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Amemiya S, Ding Z, Zhou J, Bard AJ. Studies of charge transfer at liquid|liquid interfaces and bilayer lipid membranes by scanning electrochemical microscopy. J Electroanal Chem (Lausanne) 2000. [DOI: 10.1016/s0022-0728(00)00021-8] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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1220
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Javanbakht M, Shabani-Kia A, Darvich MR, Ganjali MR, Shamsipur M. Cadmium(II)-selective membrane electrode based on a synthesized tetrol compound. Anal Chim Acta 2000. [DOI: 10.1016/s0003-2670(99)00771-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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1221
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Abstract
New salicylate-selective electrodes based on aluminum-(III) and tin(IV) salophens are described. The electrodes were prepared by incorporating the ionophores into plasticized poly(vinyl chloride) (PVC) membranes, which were directly coated on the surface of graphite electrodes. These novel electrodes display high selectivity for salicylate with respect to many common inorganic and organic anions. The influence of membrane composition and pH and the effect of lipophilic cationic and anionic additives on the response properties of the electrodes were investigated. The electrode based on aluminum salophen, with 32% PVC, 65.8% plasticizer, and 2.2% ionophore, shows the best potentiometric response characteristics and displays a linear log [Sal-] vs EMF response over the concentration range 1 x 10(-6) - 1 x 10(-1) M in phosphate buffer solutions of pH 7.0, with a Nernstian slope of -59.2 mV/decade of salicylate concentration. Highest selectivity was observed for the membrane incorporating 38.8% PVC, 57.3% plasticizer, 2.6% Sn(salophen), and 1.3% sodium tetraphenylborate. The electrodes exhibit fast response times and micromolar detection limits (approximately 1 x 10(-6) M salicylate) and could be used over a wide pH range of 3-8. Applications of the electrodes for determination of salicylate in pharmaceutical preparations and biological samples are reported.
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1222
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Xu D. Tetrabenzyl pyrophosphate as a new class of neutral carrier responsive to lead ion. Talanta 2000; 51:365-71. [DOI: 10.1016/s0039-9140(99)00286-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/1999] [Revised: 09/23/1999] [Accepted: 09/27/1999] [Indexed: 11/30/2022]
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1223
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1224
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Ahn KH, Kim SG, Jung J, Kim KH, Kim J, Chin J, Kim K. Selective Recognition of NH4+over K+with Tripodal Oxazoline Receptors. CHEM LETT 2000. [DOI: 10.1246/cl.2000.170] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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1225
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1226
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Fathi M, Darviche F, Ganjali M. Lead-Selective Membrane Potentiometric Sensor Based On A Recently Synthesized Dimethyl Benzo Tetrathia Fulvalene. ANAL LETT 2000. [DOI: 10.1080/00032710008543106] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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1227
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Fakhari AR, Alaghemand M, Shamsipur M. Zinc-Selective Membrane Electrode Based On 5, 6, 14, 15-Dibenzo-l, 4-Dioxa-8, 12-Diazacyclopentadecane-5, 14-Diene. ANAL LETT 2000. [DOI: 10.1080/00032710008543181] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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1228
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Fibbioli M, Berger M, Schmidtchen FP, Pretsch E. Polymeric membrane electrodes for monohydrogen phosphate and sulfate. Anal Chem 2000; 72:156-60. [PMID: 10655648 DOI: 10.1021/ac990696i] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A zwitterionic bis(guanidinium) ionophore bearing an anionic closo-borane cluster (1) and a dihydrochloride analogue (2) are investigated in polymeric membrane ion-selective electrodes (ISEs). Both compounds have been previously shown to complex and selectively extract oxoanions. By systematic variation of the kind and concentration of the ion-exchanger sites in the membrane, the optimal performance with the so far best sulfate selectivity is found for ISE membranes based on the dihydrochloride, whereas those with the zwitterion analogue are shown to possess a reasonably good selectivity for monohydrogen phosphate.
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Affiliation(s)
- M Fibbioli
- Department of Organic Chemistry, Swiss Federal Institute of Technology (ETH), Zürich, Switzerland
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1229
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Functionalized macrocyclic ligands as sensory molecules for metal ions. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s1068-7459(00)80015-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
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1230
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KATSU T, NISHIMURA N. Organic Ammonium Ion-Selective Electrodes Using Acyclic Neutral Carriers Developed for Inorganic Cation-Selective Electrodes. ANAL SCI 2000. [DOI: 10.2116/analsci.16.523] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Takashi KATSU
- Faculty of Pharmaceutical Sciences, Okayama University
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1231
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Morf WE, Badertscher M, Zwickl T, de Rooij NF, Pretsch E. Effects of Ion Transport on the Potential Response of Ionophore-Based Membrane Electrodes: A Theoretical Approach. J Phys Chem B 1999. [DOI: 10.1021/jp9926443] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Werner E. Morf
- Institute of Microtechnology (IMT), University of Neuchâtel, Rue Jaquet-Droz 1, CH-2007 Neuchâtel, Switzerland, and Swiss Federal Institute of Technology (ETH), Department of Organic Chemistry, Universitätstrasse 16, CH-8092 Zürich, Switzerland
| | - Martin Badertscher
- Institute of Microtechnology (IMT), University of Neuchâtel, Rue Jaquet-Droz 1, CH-2007 Neuchâtel, Switzerland, and Swiss Federal Institute of Technology (ETH), Department of Organic Chemistry, Universitätstrasse 16, CH-8092 Zürich, Switzerland
| | - Titus Zwickl
- Institute of Microtechnology (IMT), University of Neuchâtel, Rue Jaquet-Droz 1, CH-2007 Neuchâtel, Switzerland, and Swiss Federal Institute of Technology (ETH), Department of Organic Chemistry, Universitätstrasse 16, CH-8092 Zürich, Switzerland
| | - Nicolaas F. de Rooij
- Institute of Microtechnology (IMT), University of Neuchâtel, Rue Jaquet-Droz 1, CH-2007 Neuchâtel, Switzerland, and Swiss Federal Institute of Technology (ETH), Department of Organic Chemistry, Universitätstrasse 16, CH-8092 Zürich, Switzerland
| | - Ernö Pretsch
- Institute of Microtechnology (IMT), University of Neuchâtel, Rue Jaquet-Droz 1, CH-2007 Neuchâtel, Switzerland, and Swiss Federal Institute of Technology (ETH), Department of Organic Chemistry, Universitätstrasse 16, CH-8092 Zürich, Switzerland
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1232
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Mi Y, Bakker E. Determination of complex formation constants of lipophilic neutral ionophores in solvent polymeric membranes with segmented sandwich membranes. Anal Chem 1999; 71:5279-87. [PMID: 10596210 DOI: 10.1021/ac9905930] [Citation(s) in RCA: 158] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A potentiometric method to determine ionophore complex formation constants in solvent polymeric membrane phases, proposed originally by Russian researchers, is critically evaluated and compared to other established methods. It requires membrane potential measurements on two-layer sandwich membranes, where only one side contains the ionophore. The resulting initial membrane potential reflects the ion activity ratio at both aqueous phase--membrane interfaces and can be conveniently used to calculate complex formation constants in situ. This method is potentially useful, since it does not require the use of a reference ion or second ionophore in the measurement. In this paper, the five ionophores valinomycin, BME-44, ETH 2120, tert-butylcalix[4]arene tetraethyl ester, and S,S'-methylenebis(diisobutyldithiocarbamate) are characterized in poly(vinyl chloride) (PVC) plasticized with dioctyl sebacate (DOS) and compared with other established methods. The resulting formation constants correspond well to literature values. The influence of varying membrane concentrations and different anionic site additives is studied and found to be relatively small. Experiments are also performed with and without lipophilic inert electrolytes and with ionophore-free sandwich membranes to illustrate the effect of ion pairing and the membrane internal diffusion potential on the response of such sandwich membranes. These experiments suggest that ions are completely associated in PVC-DOS membranes, but that such ion pairs are rather nonspecific. Diffusion potentials seem to play a minor role with these systems. The results are explained with theory. This work indicates that the characterization of electrically charged ionophores, anion-selective ionophores, and ionophores in membrane matrixes other than PVC plasticized with DOS may now be experimentally accessible.
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Affiliation(s)
- Y Mi
- Department of Chemistry, Auburn University, Alabama 36849, USA
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1233
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Amini MK, Shahrokhian S, Tangestaninejad S. Thiocyanate-selective electrodes based on nickel and iron phthalocyanines. Anal Chim Acta 1999. [DOI: 10.1016/s0003-2670(99)00549-8] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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1234
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Shamsipur M, Khayatian G, Tangestaninejad S. Thiocyanate-Selective Membrane Electrode Based on (Octabromotetraphenylporphyrinato)manganese(III) Chloride. ELECTROANAL 1999. [DOI: 10.1002/(sici)1521-4109(199912)11:18<1340::aid-elan1340>3.0.co;2-m] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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1235
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1236
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1237
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Berger M, Schmidtchen FP. Zwitterionic Guanidinium Compounds Serve as Electroneutral Anion Hosts. J Am Chem Soc 1999. [DOI: 10.1021/ja992028k] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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1238
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In situ determination of sulfide profiles in sediment porewaters with a miniaturized Ag/Ag2S electrode. Anal Chim Acta 1999. [DOI: 10.1016/s0003-2670(99)00490-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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1239
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Mathison S, Bakker E. Renewable pH cross-sensitive potentiometric heparin sensors with incorporated electrically charged H+ ionophores. Anal Chem 1999; 71:4614-21. [PMID: 10546533 DOI: 10.1021/ac990387s] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Polymer membrane-based potentiometric sensors have been developed earlier to provide a rapid and direct method of analysis for polyions such as heparin, a natural anticoagulant administered to prevent thrombus formation during cardiovascular surgery. These heparin sensors are irreversible, requiring a membrane renewal procedure between measurements which currently prevents the sensors from being used for continuous monitoring of blood heparin. A newly developed heparin sensor is shown here to allow an alternate and more practical method of membrane renewal. The electrically charged H+ ionophore 5-(octadecanoyloxy)-2-(4-nitrophenylazo)-phenol (ETH 2412) is incorporated as an additional ionophore into a heparin-sensing membrane. This membrane will respond to pH only at low H+ concentrations, while sample anions are coextracted with H+ ions into the membrane at physiological pH. In buffered samples at physiological pH, the sensors will therefore respond to heparin via an ion-exchange mechanism with chloride anions. The pH cross-sensitive heparin-sensing membranes are shown to give an excellent potentiometric response toward heparin in aqueous samples at physiological pH and Cl-levels as well as in undiluted whole blood with no loss of heparin response. The membrane renewal is accomplished by moderately increasing the pH of the sample, causing heparin to diffuse out of the membrane with H+ ions. Reproducibilities are, with less than 1 mV standard deviation, improved over the classical system. Unlike the high NaCl concentration used to strip heparin from the previously established heparin sensor, the pH change used here could ultimately be performed locally at the sample-membrane interface, allowing the sensor to be used for automated long-term monitoring of heparin in blood. A theoretical model is presented to explain the experimental results.
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Affiliation(s)
- S Mathison
- Department of Chemistry, Auburn University, Alabama 36849, USA
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1240
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Wilke S, Wang H. Transfer of heavy metal ions across the water∣nitrobenzene microinterface facilitated by the cadmium selective ionophore ETH1062. J Electroanal Chem (Lausanne) 1999. [DOI: 10.1016/s0022-0728(99)00327-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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1241
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Shamsipur M, Rouhani S, Reza Ganjali M, Eshghi H, Sharghi H. Copper(II)-Selective Membrane Electrode Based on a Recently Synthesized Macrocyclic Diamide. Microchem J 1999. [DOI: 10.1006/mchj.1999.1784] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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1242
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Mi Y, Mathison S, Goines R, Logue A, Bakker E. Detection limit of polymeric membrane potentiometric ion sensors: how can we go down to trace levels? Anal Chim Acta 1999. [DOI: 10.1016/s0003-2670(99)00396-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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1243
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Chin J, Walsdorff C, Stranix B, Oh J, Chung HJ, Park SM, Kim K. Ein rationaler Ansatz zur selektiven Erkennung von NH4+ gegenüber K+. Angew Chem Int Ed Engl 1999. [DOI: 10.1002/(sici)1521-3757(19990917)111:18<2923::aid-ange2923>3.0.co;2-p] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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1244
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Ye Q, Borbély S, Horvai G. Microstructure of Ion-Selective Plasticized PVC Membranes Studied by Small-Angle Neutron Scattering. Anal Chem 1999; 71:4313-20. [DOI: 10.1021/ac981416m] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Qingshan Ye
- Division of Chemical Information Technology, Technical University of Budapest, H-1111 Budapest, Gellért tér 4, Hungary, and Research Institute for Solid State Physics and Optics, H-1121 Budapest, Konkoly Thege u. 29-33, Hungary
| | - Sándor Borbély
- Division of Chemical Information Technology, Technical University of Budapest, H-1111 Budapest, Gellért tér 4, Hungary, and Research Institute for Solid State Physics and Optics, H-1121 Budapest, Konkoly Thege u. 29-33, Hungary
| | - George Horvai
- Division of Chemical Information Technology, Technical University of Budapest, H-1111 Budapest, Gellért tér 4, Hungary, and Research Institute for Solid State Physics and Optics, H-1121 Budapest, Konkoly Thege u. 29-33, Hungary
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1245
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Kawakami J, Fukushi A, Ito S. Complexing Behavior of New Naphthalene Derivatives Having Amide Groups as Fluorescent Chemosensors for Alkali and Alkaline Earth Metal Ions. CHEM LETT 1999. [DOI: 10.1246/cl.1999.955] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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1246
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1247
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Jadhav S, Bakker E. Voltammetric and amperometric transduction for solvent polymeric membrane ion sensors. Anal Chem 1999; 71:3657-64. [PMID: 10489520 DOI: 10.1021/ac990195x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This paper describes basic response features of solvent polymeric membrane ion sensors with voltammetric and amperometric transduction. The model systems used here contain no ionophore for simplicity reasons. Reasonable simplifications of the theory are introduced that allow one to understand the response mechanism in view of a practical application of these sensors. It is shown that ion-sensing membranes preferentially contain no ion-exchanger properties in order to function optimally in a voltammetric mode. As with the systems studied by Kihara, both liquid-polymer interfaces of the membrane are preferably polarizable. Specifically, they contain the highly lipophilic electrolyte tetradodecylammonium tetrakis(4-chlorophenyl)borate (ETH 500) in the membrane to improve lifetime, increase the magnitude of the potential window, and prohibit exchange reactions with sample ions. An ohmic behavior that is associated with an assisted electrolyte-transfer process is observed only above a threshold potential which can be quantitatively predicted by theory. The threshold potential depends on the nature and activity of sample anions and cations in the sample and inner filling solution of the membrane electrode. Within the experimental conditions discussed in this paper, these sensors seem to measure sample ion activities, not concentrations, since the rate-limiting step is the diffusion of extracted ions away from the interface into the membrane bulk. Similarly, no effect of sample stirring on the measured current is observed. This contrasts to work done on liquid-liquid electrolyte-transfer reactions, where large diffusion coefficients in the organic phase often lead to substantial sample depletion effects. The detection of anions and cations with the same membrane is demonstrated in a cyclic voltammetric mode. Direct continuous detection of one type of anion is accomplished by pulsed amperometry to ensure a rapid, repetitive renewal of the membrane composition between measurements.
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Affiliation(s)
- S Jadhav
- Department of Chemistry, Aubuur University, Alabama 36849, USA
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1248
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Odashima K, Yagi K, Tohda K, Umezawa Y. Dopamine-selective response in membrane potential by homooxacalix[3]arene triether host incorporated in PVC liquid membrane. Bioorg Med Chem Lett 1999; 9:2375-8. [PMID: 10476872 DOI: 10.1016/s0960-894x(99)00395-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Selectivities of membrane potential changes for catecholamines and inorganic cations were investigated with lipophilic derivatives of calix[6]arene and related hosts incorporated in poly(vinyl chloride) (PVC) matrix liquid membranes. Homooxacalix[3]arene triether displayed an excellent selectivity for dopamine against other catecholamines (adrenaline, noradrenaline) and also against inorganic cations (K+, Na+).
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Affiliation(s)
- K Odashima
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Japan.
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1249
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Ceresa A, Pretsch E. Determination of formal complex formation constants of various Pb2+ ionophores in the sensor membrane phase. Anal Chim Acta 1999. [DOI: 10.1016/s0003-2670(99)00311-6] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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1250
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Kurihara K, Ohtsu M, Yoshida T, Abe T, Hisamoto H, Suzuki K. Micrometer-Sized Sodium Ion-Selective Optodes Based on a “Tailed” Neutral Ionophore. Anal Chem 1999. [DOI: 10.1021/ac981206+] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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