Properties Of Ion-selective Electrodes Research Articles

High Capacity Nanocomposite Layers Based on Nanoparticles of Carbon Materials and Ruthenium Dioxide for Potassium Sensitive Electrode.

This work presents the new concept of designing ion-selective electrodes based on the use of new composite materials consisting of carbon nanomaterials and ruthenium dioxide. Using two different materials varying in microstructure and properties, we could obtain one material for the mediation layer that adopted features coming of both components. Ruthenium dioxide characterized by high electrical capacity and mixed electronic-ionic transduction and nano-metric carbon materials were reportedly proved to improve the properties of ion-selective electrodes. Initially, only the materials and then the final electrodes were tested in the scope of the presented work, using scanning and transmission electron microscope, contact angle microscope, and various electrochemical techniques, including electrochemical impedance spectroscopy and chronopotentiometry. The obtained results confirmed beneficial influence of the designed nanocomposites on the ion-selective electrodes’ properties. Nanosized structure, high capacity (characterized by the electrical capacitance value from approximately 5.5 mF for GR + RuO2 and CB + RuO2, up to 14 mF for NT + RuO2) and low hydrophilicity (represented by the contact angle from 60° for GR+RuO2, 80° for CB+RuO2, and up to 100° for NT + RuO2) of the mediation layer materials, allowed us to obtain water layer-free potassium-selective electrodes, characterized by rapid and stable potentiometric response in a wide range of concentrations-from 10−1 to 10−6 M K+.

Investigation of poly(3,4-ethylenedioxythiophene) deposition method influence on properties of ion-selective electrodes based on bis(benzo-15-crown-5) derivatives

Glassy carbon electrodes modified by conductive polymers and membrane with derivatives of bis(benzo-15-crown-5) were tested as solid contact ion selective electrodes for K+ ions concentration determination. PEDOT with PSS, Cl− and ClO4− counter ions was electrochemically deposited onto glassy carbon substrates using four different electrochemical approaches (potentiostatic, galvanostatic, potentiodynamic and potentiostatic pulses). Scanning electron microscopy was applied to investigate influence of electrodeposition method on morphology of polymer films and drop-casted pseudo liquid membrane with an ionophore. The presence of the polymer film and method of deposition affect morphology of tested electrodes and sensing properties as well. The best sensing properties were obtained for the electrodes with biscrown I as ionophore with polymer which have a developed surface prepared via potentiostatic pulses (logKK/Na=−5.6 using separate solution method (SSM 1M)). Galvanostatic method of electrodeposition which resulted in relatively smooth layer of the PEDOT exhibited the poorest sensing properties for sensor with biscrown I as ionophore (logKK/Na=−4.3 for SSM 1M). All prepared sensors exhibited very favorable values of selectivity coefficients KK/Na (logKK/Na=−5.6 - -4.0). Detection limit equals to 10−7M was achieved. The influence of pH for sensing properties were investigated for the selected electrodes.

Ion-selective electrodes with solid contact for heavy metals determination

Potentiometric properties of ion-selective electrodes with solid contact for lead, cadmium and zinc determination were investigated. The ionic liquids (ILs) alkyl methyl imidazolium chlorides are used as lipophilic ionic additive to the membrane phase and as transducer media. The basic analytical parameters of the studied electrodes, such as the slope characteristic, the detection limit, response time, lifetime, selectivity coefficients against various inorganic cations as well as the dependence of the electrodes potential on pH were determined. The obtained electrode are characterized by good analytical parameters: theoretical characteristic slope, low detection limit, short response time and very long lifetime. The electrodes was successfully applied to the direct determination of lead, cadmium and zinc ions in waste water samples. The results obtained indicate that the electrodes provide a good alternative for the determination of these heavy metals in real samples.

Effects of architecture and surface chemistry of three-dimensionally ordered macroporous carbon solid contacts on performance of ion-selective electrodes.

The effects of the architecture and surface chemistry of three-dimensionally ordered macroporous (3DOM) carbon solid contacts on the properties of ion-selective electrodes (ISEs) were examined. Infiltration of the plasticized poly(vinyl chloride) (PVC) membrane into the pores of the carbon created a large interfacial area between the sensing membrane and the solid contact, as shown by cryo-scanning electron microscopy (cryo-SEM) and elemental analysis. This large interfacial area, along with the high capacitance of the 3DOM carbon solid contacts (as determined by cyclic voltammetry, chronopotentiometry, and electrochemical impedance spectroscopy) results in an excellent long-term stability of the potentiometric response, with drifts as low as 11.7 muV/h. The comparison of 3DOM carbon solid contacts with an untemplated carbon solid contact shows that the pore structure is an essential feature for the excellent electrode performance. However, the surface chemistry of the 3DOM carbon cannot be ignored. While there is no evidence for an aqueous layer forming between the sensing membrane and unoxidized 3DOM carbon, electrodes based on oxidized 3DOM carbon exhibit potentiometric responses with the typical hysteresis indicative of a water layer. A comparison of the different techniques to characterize the solid contacts confirms that constant-current charge-discharge experiments offer an intriguing approach to assess the long-term stability of solid-contact ISEs but shows that their results need to be interpreted with care.

A solid-state ion-selective electrode with an ionic-electronic transducer for determining chlordiazepoxide

A solid-state ion-selective electrode for determining chlordiazepoxide is described. A characteristic feature of the electrode is the presence of an intermediate conducting polymeric layer (transducer) of poly(o-aminophenol) between the ion-selective membrane with ionic conduction and a Pt conductor. The properties of ion-selective electrodes with transducers are compared with those of ISEs without transducers (coated-wire electrodes, CWEs). The most important distinctive features of ion-selective electrodes with transducers are the high stability of their potentials in time and their small sizes. The main performance characteristics of the electrode and the scope of its application are found.

Selective fluoride recognition and potentiometric properties of ion-selective electrodes based on bis(halodiphenylstannyl)alkanes

A series of bis(halodiphenylstannyl)alkanes (Ph 2XSn) 2(CH 2) n , (X: Cl, Br, OAc, n=1–4) have been evaluated as fluoride ionophores in polymeric-membrane ion-selective electrodes. It is shown that the selectivity pattern of these molecules is governed by their structural characteristics. An entirely non-Hofmeister selectivity sequence with a remarkable preference towards fluoride is obtained for bis(chlorodiphenylstannyl)methane, (Ph 2ClSn) 2CH 2. The latter compound was utilised for further studies on the improvement of the ISEs selectivity towards fluoride. The optimum membrane composition for best potentiometric performance was achieved with DOS-elasticised membranes doped with 10 mol% KTpClPB, suggesting that this compound operates via a charged-carrier mechanism. This membrane composition results in a preference to fluoride over several lipophilic anions, such as perchlorate, nitrate and iodide.

Experimental verification of the properties of ion-selective electrodes for low concentration determination.

The influence of several ion-selective electrode properties on electrode response and selectivity at low concentration levels has been investigated experimentally. The properties investigated were the composition of inner electrode solution, the composition of the membrane, the presence of interfering ions in the sample, and the thickness of diffusion layer in the sample solution. All the results obtained confirmed theoretical considerations.

Electrochemical Parameters of Ion-Exchange Membranes Selective to Anions of Sulfa Drugs

Basic electrochemical properties of ion-selective electrodes designed to assay sulfa drugs are studied. Quaternary ammonium salts containing various functional substituents are tested as the active group of an ion-exchanger. Association constants of electroactive compounds in the membrane media, solubility products, and distribution coefficients in the aqueous solution/membrane solvent system are calculated.

Ion-Selective Electrode for the Determination of Sulfadimezine

The main electroanalytical properties of ion-selective electrodes for determining sulfadimezine were studied. Quaternary ammonium salts containing different functional substituents were tested as ionophore groups in ion exchangers. The association constants of ionophores in membrane media, solubility products, and partition coefficients in the aqueous solution–membrane solvent system were calculated.

Ion-metal and ion-selective electrode properties compared on the basis of the polyelectrode model

The behaviours of ion-metal, ion-selective and film electrodes in solutions containing a redox system (Fe(CN) 6 3−/Fe(CN) 6 4−, Fe 3+/Fe 2+, quinone—hydroquinone, H 2O 2, ascorbic acid and dissolved O 2) are compared. The electrodes used are made of silver and silver halogenides and chalcogenides. The film electrodes based on silver chalcogenides and the metallic electrode had the same properties. The silver-halogenide electrode is similar to the ion-selective ones. The results are interpreted from the point of view of electrochemical kinetics and mixed conductivity depending on the stoichiometric composition.

Further studies on the potentiometric salicylate response of polymeric membranes doped with tin(IV)-tetraphenylporphyrins

The chemistry leading to the selective potentiometric response toward salicylate of polymer membranes doped with 5,10,15,20-tetraphenyl(porphyrinato)tin(IV) dichloride (Sn(TPP)Cl 2) is examined via 119Sn NMR, 3H 2O uptake, spectrophotometric, and solution conductometric techniques. The response properties of ion-selective electrodes prepared with such membranes suggest a complex mechanism of anion binding within the membrane phase. In the pure organic phase, spectroscopic data indicate that salicylate binds directly to one or both axial coordination sites of Sn(IV), displacing the initial chloride ligands. In the presence of water, however, both chloride and salicylate are displaced by water molecules, resulting in a dipositively charged metalloporphyrincation. Furthermore, conductance measurements point to the formation of salicylate—porphyrin complexes with greater than 2:1 stoichiometry. The results of these studies are discussed in conjunction with the anomalous cationic emf response of Sn(TPP)Cl 2-based membranes at high concentrations of salicylate. A response mechanism is proposed which involves outer-sphere coordination of salicylate to a diaquo ligated metalloporphyrin as a key step in the observed anion extraction/equilibrium with the membrane phase.

ChemInform Abstract: The Synthesis of Some Aromatic Crown Ether Derivatives and Their Ion‐Selective Electrode Properties.

ChemInformVolume 21, Issue 32 Heterocyclic Compounds ChemInform Abstract: The Synthesis of Some Aromatic Crown Ether Derivatives and Their Ion-Selective Electrode Properties. E. LUBOCH, E. LUBOCH Inst. Inorg. Chem. Technol. Corros., Tech. Univ. Gdansk, 80-952 Gdansk, Pol.Search for more papers by this authorA. CYGAN, A. CYGAN Inst. Inorg. Chem. Technol. Corros., Tech. Univ. Gdansk, 80-952 Gdansk, Pol.Search for more papers by this authorJ. F. BIERNAT, J. F. BIERNAT Inst. Inorg. Chem. Technol. Corros., Tech. Univ. Gdansk, 80-952 Gdansk, Pol.Search for more papers by this author E. LUBOCH, E. LUBOCH Inst. Inorg. Chem. Technol. Corros., Tech. Univ. Gdansk, 80-952 Gdansk, Pol.Search for more papers by this authorA. CYGAN, A. CYGAN Inst. Inorg. Chem. Technol. Corros., Tech. Univ. Gdansk, 80-952 Gdansk, Pol.Search for more papers by this authorJ. F. BIERNAT, J. F. BIERNAT Inst. Inorg. Chem. Technol. Corros., Tech. Univ. Gdansk, 80-952 Gdansk, Pol.Search for more papers by this author First published: August 7, 1990 https://doi.org/10.1002/chin.199032212Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume21, Issue32August 7, 1990 RelatedInformation

The synthesis of some aromatic crown ether derivatives and their ion-selective electrode properties

The synthesis of alkyl, nitro and halogeno derivatives of benzo-15-crown-5, benzo- 18-crown-6 and naphtho-15-crown-5 has been reported. Also some novel ester type bis(crown ether)s have been prepared. Some of the compounds have been characterized as electroactive substances in PVC membrane Ion-selective electrodes.

The effect of substituents in macrocyclic polyethers containing aromatic rings on ion-selective electrode properties

Ion-selective electrodes, containing derivatives of crown ethers with aromatic rings, have been investigated. The electrodes were characterized by determining their detection limits and selectivity coefficients. Thet-butyl derivative of naphtho-15-crown-5 was found to exhibit the best properties (Ld=1×10−5,KNa/K=6×10−4).

Studies on crown ether based potentiometric sensors for 4,4′-dipyridinium and related dications

Electrodes based on PVC matrix membranes containing one of six crown ethers with 2-nitrophenyl octyl ether or dibutyl phthalate solvent mediator have been studied for their potentiometric response to 4,4′-dipyridyl (DPy), diquat (DQT) and paraquat (PQT) dications. The data are discussed in terms of quality of potentiometric response related to conformational phenomena of crown ethers in their complexation with these dications.Good ion-selective electrode properties were characteristic of the 4,4′-DPy systems based on bis(metaphenylene-32-crown-10)(BMP32C10), bis(metaphenylene-38-crown-12)(BMP38C12), bis(paraphenylene-34-crown-10)(BPP34C10), bis(paraphenylene-37-crown-11)(BPP37C11) and dinaphthalene-36-crown-10 (DN36C10). The calibration slope was between 33 and 41 mV decade–1, extending down to 1.7–6 µM. Interferences from potassium, ammonium, guanidinium, barium, DQT and PQT ions were low except for the BPP34C10 electrode where DQT caused some interference. A sixth electrode, based on dibenzo-30-crown-10 (DB30C10), showed similar calibration behaviour towards 4,4′-DPy but was much less selective.

Cationic complexes of nonylphenoxypoly(ethyleneoxy)ethanol: Extraction into dichloromethane and ion-selective electrode properties

Tetraphenylborate (TPB) salts of calcium, strontium and barium complexes of nonylphenoxypoly(ethyleneoxy)ethanol (NP) have been prepared from the commercially available Antarox range of NPs and screened for their suitability as ion-selective electrode sensors. For selectivity and general ion-selective electrode response behaviour, the best systems are those involving the barium complexes for barium ion response. TPB salts of calcium and barium complexes of dicyclohexyl-18-crown-6 have also been prepared. The complexing tendency of NPs, dicyclohexyl-18-crown-6 and Antarox with alkali metal and alkaline earth metal cations is described in terms of partitioning the picrates of the metal ion complexes from aqueous chloride solutions between water and dichloromethane. As well as percentage picrate extraction, the “bulk extraction constants” show the affinity of dicyclohexyl-18-crown-6 for alkali metal and alkaline earth cations to vary in the order K > Rb > Cs > Na > Li and Ba > Sr > Be > Ca > Mg, respectively, with the position of beryllium being anomalous and possibly related to the extraction of beryllium into the organic layer even in the absence of coordinating polyether or NP. For the Antarox NPs, the sequences are Rb > K > Cs > Na > Li and Be ⪢ Ba > Sr > C a > Mg, respectively.