Novel Copper(II)‐Selective Membrane Electrode Based on a New Synthesized Schiff Base

A PVC membrane electrode for copper(II) ion based on a recently synthesized Schiff base as a suitable ion carrier was constructed. The electrode exhibits a Nernstian slope of 28.3 ± 0.6 mV per decade of Cu²⁺ over a wide concentration range of 7.0 × 10^?6‐2.6 × 10^?2 M with a detection limit of 5.0 × 10^?6M in the pH range of 4.2–5.8. The response time is about 10s and it can be used for at least 1 month without any considerable divergence in potential. It was successfully applied as an indicator electrode in the potentiometric titration of copper ions.     

Lead-Selective Membrane Potentiometric Sensor Based on a Recently Synthesized Bis(Anthraquinone) Sulfide Derivative

Abstract

A new PVC membrane electrode for lead ions, based on bis[(1-hydroxy-9,10-anthraquinone)-2-methyl]sulfide as membrane carrier, was prepared. The sensor exhibits a Nernstian response for Pb²⁺ over a wide concentration range (5.6 × 10^?3-4.0 × 10^?6 M). It has a response time of about 30 s and can be used for at least 3 months without any divergence in potentials. The proposed membrane sensor revealed good selectivities for Pb²⁺ over a wide variety of other metal ions. It was used as an indicator electrode in potentiometric titration of lead ion.     

Preparation of Cu (II) imprinted polymer electrode and its application for potentiometric and voltammetric determination of Cu (II)

The Cu (II) imprinted polymer glassy carbon electrode (GCE/Cu-IP) was prepared by electropolymerization of pyrrole at GCE in the presence of methyl red as a dopant and then imprinting by Cu²⁺ ions. This electrode was applied for potentiometric and voltammetric detection of Cu²⁺ ion. The potentiometric response of the electrode was linear within the Cu²⁺ concentration range of 3.9 × 10^?6 to 5.0 × 10^?2 M with a near-Nernstian slope of 29.0 mV decade^?1 and a detection limit of 5.0 × 10^?7 M. The electrode was also used for preconcentration anodic stripping voltammetry and results exhibited that peak currents for the incorporated copper species were dependent on the metal ion concentration in the range of 1.0 × 10^?8 to 1.0 × 10^?3 M and detection limit was 6.5 × 10^?9 M. Also the selectivity of the prepared electrode was investigated. The imprinted polymer electrode was used for the successful assay of copper in two standard reference material samples.     

Lead-Selective Membrane Potentiometric Sensor Based On A Recently Synthesized Dimethyl Benzo Tetrathia Fulvalene

ABSTRACT

A PVC membrane electrode for lead ion based on dimethyl benzo tetrathia fulvalene(DMBTTF)as membrane carrier was developed. The electrode exhibits a Nernstian response for Pb^2? over a wide concentration range (10^?2?10^?5 M) with a limit of detection of 8^*10^?6M. It has a response time of 20s and can be used for at least 2 months without any considerable divergence in potentials. The proposed membrane sensor revealed good selectivities for Pb^2? over a wide variety of other metal ions and could be used in pH range of 3.0-6.0.     

Lead(II)-Selective Membrane Electrode Based on Tetraphenylporphyrin

ABSTRACT

A PVC membrane electrode for Pb² ions based on tetraphenylporphyrin was prepared. The sensor exhibits a Nernstian response for lead ions over a wide concentration range (1.0 x 10^?5-1.0 x 10^?2 M). The limit of detection is 8.5 x 10^?6M. It has a response time of 15 s and can be used for at least three months without any divergence in potential. The proposed electrode shows a fairly good discriminating ability towards Pb² ion in comparison to some alkali, alkaline earth, transition and heavy metal ions. The electrode can be used in the pH range 5.0 to 7.5. It was used as an indicator electrode in potentiometric titration of lead ion.     

Nickel(II) Ion-Selective Electrode Based on 2,5-Thiophenyl bis(5-tert-Butyl-1,3-Benzoxazole

ABSTRACT

A PVC membrane sensor for Nickel (II) ions based on 2,5-thiophenyl bis(5-tert-butyl-1,3-benzoxazole) as membrane carrier was prepared. The sensor exhibits a Nernstian response for Ni²⁺ ions over a wide concentration range (10^?2–10^?5M). It has a relatively fast response time and can be used for at least 2 months without any considerable divergence in potentials. The nature of the plasticizer, the additive, the concentration of internal solutions in the electrodes and the composition of the membrane were investigated. The proposed membrane electrode revealed very good selectivities for Ni²⁺ over a wide variety of other metal cations and could be used in pH range of 4.0–8.0. It was successfully applied for the direct determination of Ni²⁺ in solution and as an indicator electrode in potentiometric titration of nickel ion in both water and 85% acetonitrile solutions.     

Electrochemical Determination of Copper(II) in Water Samples Using a Novel Ion-Selective Electrode Based on a Graphite Oxide–Imprinted Polymer Composite

A novel copper(II)-selective electrode based on graphite oxide/imprinted polymer composite was developed for the electrochemical monitoring of copper(II) (Cu²⁺) ions. The electrode exhibited highly selective potentiometric response to Cu²⁺ with respect to common alkaline, alkaline earth and heavy metal cations. The composite composition studies indicated that the most suitable composite composition performing the most promising potentiometric properties was 20.0% ionophore (Cu²⁺-ion imprinted polymer), 10.0% paraffin oil, 5.0% multiwalled carbon nanotubes, and 65.0% graphite oxide. The fabricated electrode exhibited a linear response to Cu²⁺ over the concentration range of 1.0?×?10^??6–1.0?×?10^??1?M (correlation coefficient of 0.9998) with a sensitivity of 26.1?±?0.9?mV decade^??1. The detection limit of the fabricated electrode was determined to be 4.0?×?10^??7?M. The electrode worked well in the pH range of 4.0–8.0. The electrode had stable, reversible and fast potentiometric response (3?s). In addition, the electrode had a lifetime of more than 1 year. The analytical applications of the proposed electrode were performed using as an indicator electrode for the potentiometric titration of Cu²⁺ with ethylene diamine tetraacetic acid solution and for the determination of Cu²⁺ of spiked river, dam, and tap water samples. The obtained results for potentiometric titration and water samples were satisfactory.     

Mercury-selective membrane electrode based on methyl substituted dibenzo tetraphenyl tetraaza macrocycle

A new polystyrene based membrane electrode of methyl substituted 6,7:13,14-dibenzo-2,4,9,11-tetraphenyl-1,5,8,12-tetraazacyclotetradeca-1,4,6,8,11,13-hexaene (I) with sodium tetraphenylborate (NaTPB) and dibutyl phthalate (DBP) as anion excluder and plasticizing agent was prepared and investigated as Hg (II)-selective electrode. The electrode exhibits a Nernstian response for Hg (II) ions over a wide concentration range of 1.0 × 10⁻¹–8.9 × 10⁻⁶ M with a slope of 30 ± 1 mV per decade concentration. It has a response time of 10 s and can be used for at least 4 months without any divergence in potentials. The membrane works satisfactorily in a partially non-aqueous medium up to a maximum 30% (v/v) content of methanol and ethanol. The proposed sensor revealed good selectivity over a wide variety of other cations including alkali, alkaline earth, heavy and transition metal ions and could be used in a pH range of 2.5–5.0. Normal interferents like Ag⁺, Cd²⁺ and Pb²⁺ low interfere in the working of the electrode. The electrode was successfully used in the direct determination of Hg²⁺ in aqueous solution.     

New Potentiometric Membrane Sensors Responsive to Pb(Ii) Based on Some Recently Synthesized 9, 10- Anthraquinone Derivatives

ABSTRACT

New potentiometric membranesensorsresponsive to Pb(II) have been developed. The membrane sensors are based on three different 9, 10-anthraquinone derivatives. The electrode based on 1, 4-bis (prop-2¹-enyloxy)-9, 10-anthraquinone exhibits a good Nernstian response for Pb(II) ions over a wide concentration range (2.5×10^?6 - 1.0×10^?2 M) with a slope of 29.8 mV decade^?1. Detection limit is 1.5×10^?6 M. The response time of the sensor is 15s and the useful working pH range is 4.7-6.8. The membrane can be used for more than 4 months without any considerable divergence in potentials. The electrodes revealed comparatively good selectivities with respect to alkali, alkaline earth and some transition and heavy metal ions. It was used as an indicator electrode in potentiometric titration of lead ions (with sulfate and oxalate ions), and for the determination of lead in waste waters.     

Cobalt(II)-selective membrane electrode based on N,N′-di(thiazol-2-yl)formimidamide

A new PVC-membrane electrode for Co²⁺ ions based on N,N′-di(thiazol-2-yl)formimidamide (TF) as membrane carrier has been developed. The electrode resulted in Nernstian response (29.5?±?0.4?mV decade^?1) for Co²⁺ ion over a wide concentration range (2.5?×?10^?7 ?1.0?×?10^?1?M) with a detection limit of 6.1?×?10^?8?M. The sensor has a response time of about 10?s, and can be used for at least 2 months without observing any deviation from the Nernstain response. The electrode revealed good selectivity towards cobalt(II) ion over a wide variety of alkali, alkaline earth, transition, and heavy metal ions and could be used in the pH range 2.0–7.0. The electrode was used for determination of Co²⁺ in real samples.     

Copper(II) ion selective electrode based on a newly synthesized Schiff-base chelate

A new Cu (II) ion-selective electrode has been fabricated in poly (vinyl chloride) matrix based on a recently synthesized Schiff-base chelate. The addition of sodium tetraphenylborate (NaTPB) and various plasticizers viz. TBP, TEHP, DOS, and CN have been found to substantially improve the performance of the electrode. The membrane of various compositions of the ionophore (I) were investigated and it was found that the best performance was obtained with the membrane having (I): PVC: NaTPB: CN in the ratio 4: 140: 3: 80 (mg). The electrode exhibits a Nernstian response over a wide concentration range (1.9 × 10⁻⁶–1.0 × 10⁻¹ M) with 30.0 mV/decade of concentration between pH 3.0 and 7.5. The response time of the electrode is about 12 s and it can be used over a period of 3 months without any divergence in potential. The potentiometric selectivity coefficient values as determined by fixed interference method indicate excellent selectivity for Cu²⁺ ions over interfering cations. The electrode has also been used successfully in partially non-aqueous media having a 25% (v/v) methanol, ethanol or acetone content without showing any considerable change in the value of slope or working concentration range. The electrode has been used in the potentiometric titration of Cu²⁺ with EDTA.     

Terbium(III) Ion-Selective Electrochemical Sensor Based on Hematoporphyrin

Abstract

A polyvinyl chloride (PVC) based membrane sensor for terbium ions was prepared by employing Hematoporphyrin (HP) as an ionophore. The sensor revealed a very good selectivity (expect for the Fe³⁺ion) with respect to common alkali, alkaline earth and heavy metal ions. The plasticized membrane electrode exhibits a Nernstian response for Tb³⁺ ions over a wide concentration range (1.0 × 10^?6 ? 1.0 × 10^?2 M) with a slope of 19.8±0.3 mV per decade and low detection limit of 7.4 × 10^?7 M. The developed sensor was used in determination of F^? in mouth wash preparation sample.     

Used a new aza-thia-macrocycle as a suitable carrier in potentiometric sensor of copper (II)

A new modified carbon paste electrode for determination of Cu²⁺ made in our laboratory that used a new synthesized macrocycle 7,16-diaza-1-thia-4,10,13,19-tetraoxa-6,17-dioxo-2,3;20,21-dinaphtho-cyclouneicosane as modifier. This sensor exhibits a good affinity toward copper (II) ions over a wide variety of other metal ions. The electrode exhibits a Nernstian slope of 30 (±0.5) mV per decade for copper (II) ions over a wide concentration range (1.0 × 10^?8–1.0 × 10^?2 mol L^?1), with a limit of detection of 7.0 × 10^?9 mol L^?1 (~0.45 ppb). It has a response time of 30 s and can be used for at least 3 months without any considerable divergence in responses. The potentiometric response of the electrode is independent of the pH of test solution in the pH range 3.5–7.5. Finally, it was successfully used as an indicator electrode for determination of copper (II) in real samples such as Karoun river and tap water.     

Potentiometric flow-injection determination of copper-complexing organic ligands with a copper-wire indicating electrode

The potentiometric response of a copper-wire indicator electrode in a flow-injection system with a phosphate-buffered carrier stream can be used to determine copper-complexing ligands; glycine, histidine, L-cysteine, EDTA, ethylenediamine, triethylenetetramine, dopamine and imidazole are discussed. The electrode response is shown to give peak potentials with a Nernstian relationship to total injected ligand concentration over limited ranges, depending on the stoichiometry, stability, and oxidation state of the copper complexes formed. Galvanostatic measurements showed that complex formation with Cu²⁺ or Cu⁺ or mixed species can be responsible for the response characteristics. The effects of adding 0.1 M sodium chloride to the carrier stream are generally beneficial, particularly in obtaining sharper responses. Detection limits can be improved to about 10^?5 M by adding about 10^?5 M Cu²⁺ to the carrier stream, but the linear range of Nernstian response is then narrow.     

Development of Nalbuphine‐Selective Membrane Electrode and Its Applications in Pharmaceutical Analysis

Abstract

A nalbuphine ion‐selective PVC membrane electrode based on ion‐pair complex of nalbuphine with tetra phenyl borate was prepared with di‐butyl sebacate as a plasticizer. The electrode exhibits a linear response with a Nernstain slope 59.6 mV decate^?1 at 25°C with the concentration range of 1×10^?6?1×10^?2 M nalbuphine. The electrode response was not sensitive to pH changes from 3.5–7 and not affected by possible interfering species such as common inorganic cations, sugars and amino‐acids. The electrode shows good stability, reproducibility and fast response. These characteristics of the electrode enable it to be used successfully for the determination of nalbuphine hydrochloride in pure form and in pharmaceutical preparations.     

A Novel PVC‐Membrane‐Coated Graphite Sensor Based on an Anthraquinone Derivative Membrane for the Determination of Lead

A highly selective membrane electrode for the determination of ultratrace amounts of lead was prepared. The PVC membrane electrode based on 2‐(2‐ethanoloxymethyl)‐1‐hydroxy‐9,10‐anthraquinone (AQ), directly coated on graphite, exhibits a good Nernstian response for Pb(II) ions over a very wide concentration range (1.0×10^?7–1.0×10^?2 M) with a limit of detection of 8.0×10^?8 M. It has a fast response time of ca. 10 s and can be used over a period 2 months with good reproducibility (SD=±0.2 mV). The electrode revealed a very good selectivity respect to common alkali, alkaline earth, transition and heavy metal ions and could be used in the pH range of 3.5–6.8. It was used as an indicator electrode in potentiometric titration of lead ions with chromate and oxalate, and in indirect determination of lead in spring water samples.     

Silver(I)‐Selective PVC Membrane Potentiometric Sensor Based on a Recently Synthesized Calix[4]arene

A new PVC membrane potentiometric sensor for Ag(I) ion based on a recently synthesized calix[4]arene compound of 5,11,17,23‐tetra‐tert‐butyl‐25,27‐dihydroxy‐calix[4]arene‐thiacrown‐4 is developed. The electrode exhibits a Nernstian response for Ag(I) ions over a wide concentration range (1.0×10^?2?1.0×10^?6 M) with a slope of 53.8±1.6 mV per decade. It has a relatively fast response time (5–10 s) and can be used for at least 2 months without any considerable divergence in potentials. The proposed electrode shows high selectivity towards Ag⁺ ions over Pb²⁺, Cd²⁺, Co²⁺, Zn²⁺, Cu²⁺, Ni²⁺, Sr²⁺, Mg²⁺, Ca²⁺, Li⁺, K⁺, Na⁺, NH₄⁺ ions and can be used in a pH range of 2–6. Only interference of Hg²⁺ is found. It is successfully used as an indicator electrode in potentiometric titration of a mixture of chloride, bromide and iodide ions.     

Determination of Hg(II) ions in water samples by a novel Hg(II) sensor,based on calix[4]arene derivative

A PVC membrane electrode for Hg(II) ions, based on a new cone shaped calix[4]arene (L) as a suitable ionophore was constructed. The sensor exhibits a linear dynamic in the range of 1.0 × 10^?6–1.0 × 10^?1 M, with a Nernstian slope of 29.4 ± 0.4 mV decade^?1, and a detection limit of 4.0 × 10^?7 M. The response time is quick (less than 10 s), it can be used in the pH range of 1.5–4, and the electrode response and selectivity remained almost unchanged for about 2 months. The sensor revealed comparatively good selectivity with respect to most alkali, alkaline earth, and some transition and heavy metal ions. It was successfully employed as an indicator electrode in the potentiometric titration of Hg²⁺ ions with potassium iodide, and the direct determination of mercury content of amalgam alloy and water samples.     

A Heterogeneous Precipitate Based Mn(Ii) Coated Wire Ion-Selective Electrode

Abstract

A new heterogeneous Mn(II) ion selective coated wire electrode (CWISE) based on tetrapyridine Mn(II) thiocynanate as electroactive material has been described. the working pH range of the electrode is 2.3 to 8.8. the electrode shows a linear response in the concentration range 1.0×10^?1M to 1.0×10^?6M. the response time of the electrode is 35 sec. the selectivity coefficient for different cations determined by mixed solution method are:

Fe²⁺(0.05), Cd²⁺(0.05), Ni²⁺(0.01), Co²⁺(0.5), Pb²⁺(0.5), Hg²⁺(0.05), Sn²⁺(0), Zn²⁺(0)

The electrode can be used for the electrometeric determination of Mn(II) ion.     

Application of 2‐(benzyliminomethyl)‐6‐methoxy‐4‐(4‐methoxyphenyl‐azo)phenol in construction of ion‐selective PVC membrane electrode for determination of copper (II) in mineral water sample

The potentiometric characteristics of a new Cu²⁺‐selective electrode based on 2‐(benzyliminomethyl)‐6‐methoxy‐4‐(4‐methoxyphenyl‐azo) phenol as an efficient ionophore has been evaluated. The effects of influential parameters on the potentiometric responses such as the amount of plasticizer, the amount of ionophore, pH of the sample solution, and the effect of coexisting ions on the electrode signal were subsequently investigated . The selectivity of the electrode was assessed by calculating the selectivity coefficients using the matched potential method. The optimum ratio of the amount of materials required for the preparation of the electrode was found to be 1.7: 32.1: 64.2: 2.0 corresponding to carboxylated PVC, dimethyl sebacate as solvent mediators, potassium tetrakis (p‐chlorophenyl) borate as the anion localizing agent, and ionophore, respectively. The electrode had a fast response (7s) as well as a satisfactory Nernstian slope (29.26±0.91 mV/decade) to Cu²⁺ over a wide concentration range of 2.0×10^?6‐ 5.0×10^?2 M with a low detection limit of 5.9×10^?7 M. The developed sensor was successfully used for the potentiometric titration of Cu²⁺ ion with EDTA and subsequently, efficient determination of this metal ion in a mineral water sample was performed.