Analytical Study of a Picrate Ion Selective Membrane Electrode Using Chloride as Reference Anion

Abstract

A series of anion selective electrodes of the liquid membrane type have been examined with respect to selectivity characteristics. The resulting selectivity data are examined in terms of theory of liquid membrane electrodes and correlations are made with extraction constants.     

Sulfonamides as Ionophores for Ise. III. Guanidinium Ion-Selective Electrodes Based on Lipophilic Bis-Sulfonamide Podands

Abstract

PVC membrane ion-selective electrodes based on bis-sulfonamide podands and DOS (Bis(2-ethylhexyl)-sebacate) as plasticizer are described. They were found to behave as guanidinium ion sensors, exhibiting high selectivity for guanidinium ions over potassium ions.     

Sodium Ion-Selective Chalcogenide Glass Electrodes

Abstract

Analytical characteristics and sensing mechanism of sodium ion-selective electrodes based on NaCl-Ga₂S₃-GeS₂ glasses have been investigated. Chalcogenide glass electrodes containing 10 mol.% NaCl in the membrane showed near-Nernstian response in the concentration range from 10-³ to 1 M sodium nitrate solution. These sensors were superior to the conventional pNa oxide glass electrodes in selectivity in the presence of hydrogen ions and in Na⁺ ion sensitivity in fluoride media. Prolonged solution treatment for several days reduces, however, the detection limit of the sensors and the slope of the electrode response. Ionic processes at the membrane surface have been investigated using XPS technique and ²²Na tracer measurements. It was shown that sodium ion-exchange governed Na⁺ ion response of chalcogenide     

Selective Liquid and (Vinyl-Chloride) Pentoxyverine Membrane Electrodes - Their Preparation and Use for the Potentiometric Determination of Pentoxyverine Citrate

Abstract

The use of liquid and poly(vinyl-chloride) membrane electrodes which are sensitive and reasonably selective for pentoxyverine determination is described here. The electrodes are based on the use of pentoxyverine-picrate, pentoxyverine-picrolonate and pentoxyverine-tetraphenylborate ion association complexes as electroactive materials in nitrobenzene or in poly(vinyl chloride) matrix. These electrodes show near Nernstian response values in different concentration ranges, depending on the nature of the used counter-ions, at 3.3–7.8 pH range. Potentiometric determination of pentoxyverine citrate with use of these electrodes gives good results which later on are compared with those obtained by non-aqueous titration.     

1,3,4-Trisubstituted-2-azetidinone Derivatives as Novel Receptors for Bismuth(III) Ion-Selective Electrodes: Application in Pharmaceutical and Glass Samples

Abstract

Polymeric membrane electrodes (PMEs) and coated graphite electrodes (CGEs) containing 1,3,4-trisubstituted-2-azetidinone derivatives as ion carriers are reported here for bismuth(III) ion selectivity. These electrodes exhibited Nernstian response for Bi³⁺ ions over a wide concentration range (5.0 × 10^?7 M to 1.0 × 10^?1 M for CGE) with a lower detection limit of 3.98 × 10^?7 M (for CGE) and wide pH range (1.3–5.0). Compared to polymeric membrane electrode, the coated graphite electrode has shown better selectivity for Bi³⁺ ions with respect to common metal ions. Proposed electrodes have been used for the estimation of Bi³⁺ ions in pharmaceutical and glass samples.     

Fabrication of Membrane Sensitive Electrodes for the Validated Electrochemical Quantification of Anti-Osteoporotic Drug Residues in Pharmaceutical Industrial Wastewater

Accurate and precise application of ion-selective electrodes (ISEs) in the quantification of environmental pollutants is a strenuous task. In this work, the electrochemical response of alendronate sodium trihydrate (ALN) was evaluated by the fabrication of two sensitive and delicate membrane electrodes, viz. polyvinyl chloride (PVC) and glassy carbon (GC) electrodes. A linear response was obtained at concentrations from 1 × 10⁻⁵ to 1 × 10⁻² M for both electrodes. A Nernstian slope of 29 mV/decade over a pH range of 8–11 for the PVC and GC membrane electrodes was obtained. All assay settings were carefully adjusted to obtain the best electrochemical response. The proposed technique was effectively applied for the quantification of ALN in pure form and wastewater samples, acquired from manufacturing industries. The proposed electrodes were effectively used for the determination of ALN in real wastewater samples without any prior treatment. The current findings guarantee the applicability of the fabricated ISEs for the environmental monitoring of ALN.     

Sodium Ion Selective Electrodes Based on Lipophilic 16-Crown-5 Derivatives

Abstract

Six kinds of lipopholic 16-crown-5 derivatives possessing double side-chains were synthesized. The Na⁺-selectivities were examined with poly(vinyl chloride) (PVC) matrix-membrane electrodes using these crown compounds. It is an effective way for obtaining high Na⁺-selectivity by introducing a bulky side-chain such as a benzyloxymethyl group into the 16-crown-5. The electrodes based on 16-crown-5 derivatives having both a methyl or ethyl group and a benzyloxymethyl group at the pivot carbon (C-15) (3 or 4, see Figure 1) exhibited excellent Na⁺-selectivity over K⁺ (log k _Na.x = -2.65 and -2.75 for 3 and 4, respectively).     

Structural Selectivity of Calix[m]pyrroles[n]furans (m + n = 4) as Ionophores in Ag(I) Ion-Selective Electrodes

A series of octamethylcalix[m]pyrroles[n]furans (m + n = 4), such astrans-octamethylcalix[2]pyrroles[2]furans L ₁ ),cis-octamethylcalix[2]pyrroles[2]furans (L ₂ ) and octamethylcalix[1]pyrrole[3]furans (L ₃ ) have been studied as sensors in liquid membrane ion-selective electrodes for Ag(I) ion. The electrode based on L ₁ , trans-N₂O₂ porphyrinogen, gave the best results with a wide working concentration range of 1.0 × 10^-1 - 1.0 × 10^5.6 M and a Nernstian slope of 57.0 mV/decade. This electrode exhibited a fast response time of 30 s and high selectivity over a number of mono-, di- and tri-valent cations, with only Tl(I) and Hg(II) ion interferences. The effect of anion excluders on the performance of the membrane electrodes has been also studied. The electrode based on L ₁ showed no significant potential changes in the range 2.5 < pH < 7.5. The crystalstructure of L ₃ , NO₃ porphyrinogen, was determined by single crystal X-ray analysis. The crystallographic analysis of L ₃ reveals that its structure is a saddle-shaped 1,3-alternate conformation with enough space to accommodate Ag(I) in the three dimensional cavity.     

Poly (Vinyl Chloride) Matrix Membrane Electrodes Responsive to Thiocyanate,Perchlorate and Periodate

Abstract

Three types of PVC matrix membrane ion-selective electrodes (ISEs) are described. These are based on membranes containing nitron thiocyanate with 2-nitro-phenyl phenyl ether, 2-nitrophenyl phenyl ether alone and tetraphenylarsonium thiocyanate with 2-nitrophenyl octyl ether. Each type is conditioned and stored in 0.1M sodium thiocyanate. The first two electrodes have been evaluated for thiocyanate and perchlorate response and the best linear long range (linear range down to 2.5×10^?5M) response was obtained for perchlorate. The third electrode is suitable as a periodate ISE with linear calibration range down to 2×10^?4M. The plasticized (2-nitrophenyl phenyl ether) PVC electrode for thiocyanate and perchlorate had a much longer pH interference free range (1.5–12.5) than either of the other electrodes.     

Progress In Phosphate-Selective Electrode Development

Abstract

The responses of polymer membrane electrodes containing dibenzyltin dichloride derivatives to phosphate and chloride are given. When compared with electrodes containing a conventional anion-exchanger electroactive species, the organotin- based electrodes clearly exhibit superior selectivity for dibasic phosphate relative to chloride.     

Litcrosomal Nadph Oxidase and Hybrid Electrodes

Abstract

The NADPH oxidizing activity of rat liver microsomes was investigated and found to be mainly due to the cytochrome P-450 system. The XADPH oxidase was utilized for the development of several organelle electrodes. Gelatin membrane immobilized microsomes were combined with an O₂ membrane sensor for bioelectrochemical measurement of NADPH. The dependence of the current on substrate concentration was linear up to 1 mmol·1^?1 To assemble hybrid electrodes for determination of glucose-6-phoaphate, ATP and isocitrate pure enzymes were coimmobilized with the microsomal fraction.     

Highly Selective Chromium(III) PVC‐Membrane Electrodes Based on Some Recently Synthesized Schiff's Bases

Three recently synthesized Schiff's bases were studied to characterize their ability as Cr³⁺ ion carrier in PVC‐membrane electrodes. The polymeric membrane (PME) and coated glassy carbon (CGCE) electrodes based on 2‐hydroxybenzaldehyde‐O,O′‐(1,2‐dioxetane‐1,2‐diyl) oxime (L1) exhibited Nernstian responses for Cr³⁺ ion over wide concentration ranges (1.5×10^?6–8.0×10^?3 M for PME and 4.0×10^?7–3.0×10^?3 M for CGCE) and very low limits of detection (1.0×10^?6 M for PME and 2.0×10^?7 M for CGCE). The proposed potentiometric sensors manifest advantages of relatively fast response and, most importantly, good selectivities relative to a wide variety of other cations. The selectivity behavior of the proposed Cr³⁺ ion‐selective electrodes revealed a considerable improvement compared to the best previously PVC‐membrane electrodes for chromium(III) ion. The potentiometric responses of the electrodes are independent of pH of the test solution in the pH range 3.0–6.0. The electrodes were successfully applied to determine chromium(III) in water samples.     

Solid Membranes of Copper Hriacyanoferrats (III) as Thallium (I) Sensitive Electrode

Abstract

Solid membranes of copper hexacyanoferrate (III) in Areldite are evaluated as thallium (I) sensitive electrode. The membrane electrode gave a linear near Normstian response to thallium (I) ions in the concentration range 10^?1 - 5 × 10^?4 M and can be used to estimate T1 (I) down to 10^?4 M. The responses of the electrode is fast and steady potentials are obtained in less than a minute. The same membrane has been used over a period of six months without any appreciable drift in potential. The electrode can also be used satisfactory in partially non-aqueous media and in presence of a number of interfering ions. It is superior to the existing T1(I) solid membrane electrodes as it can function in alkaline range also.     

FIA Potentiometric and Solvent Extraction Studies of Alkali Metal and Alkaline Earth Cation Complexation by bis(Tert-butylbenzo)-21-crown-7

Abstract

A flow injection analysis study of the potentiometric selectivity of bis[4(5)-tert-butylbenzo]-21-crown-7 (D(tBB)21C7) for cesium over the other alkali metal cations and three alkaline earth cations has been conducted. A PVC matrix membrane containing D(tBB)21C7 as an ionophore was coated on the tip of a silver wire incorporated in a flow cell. No selectivity for cesium over rubidium and only low selectivity over potassium were noted. However, very high selectivities for cesium over sodium, lithium, strontium, calcium, and magnesium were observed. Selectivity of D(tBB)21C7 in the solvent extraction of alkali metal cations was determined by the picrate extraction method. The percent extraction into deuteriochloroform decreased in the order cesium, rubidium > potassium » sodium » lithium. Thus good agreement was observed between the responses of D(tBB)21C7 towards alkali metal cations in polymeric membrane electrodes and in solvent extraction.     

含嘧啶环的双冠醚——V.双冠醚为载体的碱金属离子选择性电极的研究

本文报道由5-硝基-6-三氟甲基嘧啶环桥联苯并-12-冠-4、苯并-15-冠-5和苯并-18-冠-6的三种新的双冠醚的合成。用它们作为载体分别制成钠、钾和铯离子选择性电极，测定了电极的响应功能、选择性系数和适用的pH范围。结果表明三种电极都有较好的性能。     

[Cu(L)](NO3)2 (L=4,7‐Bis(3‐aminopropyl)‐1‐thia‐4,7‐diazacyclononane) as a Suitable Ionophore for Construction of Thiocyanate‐Selective Electrodes and Their Use in Determination of Urinary and Salivary Thiocyanate Concentration

The construction, performance characteristics, and application of polymeric membrane (PME) and coated graphite (CGE) thiocyanate‐selective electrodes are reported. The electrodes were prepared by incorporating the complex [Cu(L)](NO₃)₂ (L=4,7‐bis(3‐aminopropyl)‐1‐thia‐4,7‐diazacyclononane) into a plasiticized poly(vinyl chloride) membrane. The influence of membrane composition, pH of test solution, and foreign ions were investigated. The electrodes reveal Nernstian behavior over a wide SCN^? ion concentration range (1.0×10^?6–1.0×10^?1 M for PME and 5.0×10^?7–1.0×10^?2 M for CGE) and show fast dynamic response times of 15 s and lower. The proposed sensors show high selectivity towards thiocyanate over several common organic and inorganic anions. They were successfully applied to the direct determination of thiocyanate in urine and saliva of smokers and nonsmokers, and as an indicator electrode in titration of Ag⁺ ions with thiocyanate.     

Highly Selective Sodium Ion Responsive Glass Electrode

Abstract

A highly selective electrode glass for the measurement of sodium ion activity is described. The corresponding glass electrodes shew a selectivity for sodium over hydrogen ions of about 10 and for sodium over potassium ions of about 10,000.     

Room Temperature Ionic Liquids (RTILs) and Multiwalled Carbon Nanotubes (MWCNTs) as Modifiers for Improvement of Carbon Paste Ion Selective Electrode Response; A Comparison Study with PVC Membrane

Room temperature ionic liquids (RTILs), 1‐n‐butyl‐3‐methylimidazolium tetrafluoroborate, [bmim]BF₄, and multiwalled carbon nanotubes (MWCNTs) were used for improvement of a praseodymium carbon paste ion selective sensor response. [bmim]BF₄ can be a better binder than mineral oils. MWCNTs have a good conductivity which helps the transduction of the signal in carbon paste electrode. The characteristics of these electrodes as potentiometric sensors were evaluated and compared with PVC membrane sensor. The results indicate that potentiometric sensor constructed with ionic liquid shows an increase in performance in terms of Nernstian slope, selectivity, response time, and response stability compared to Pr(III) PVC membrane sensor.     

含嘧啶环的双冠醚 V.双冠醚为载体的碱金属离子选择性电极的研究

本文报道由５－硝基－６－三氟甲基嘧啶环桥联苯并－１２－冠－４、苯并－１５－冠－５和苯并－１８－冠－６的三种新的双冠醚的合成。用它们作为载体分别制成钠、钾和铯离子选择性电极，测定了电极的响应功能、选择性系数和适用的ｐＨ范围。结果表明三种电极都有较好的性能。     

含嘧啶环的双冠醚——Ⅲ.用双冠醚作载体的PVC膜离子选择性电极性质的研究

合成了九种用嘧啶环桥联的新的双冠醚,其中分别含有苯并-12-冠-4、(1、47)、苯并-15-冠-5(2、5、8)和苯并-18-冠-6(3、6、9 )。用它们作为载体分别制成钠、钾和铯离子选择性电极,测定了电极的选择性系数。结果表明,电极(7)(8)(9)具有较好的性能。