Erbium(III) PVC Membrane Ion-Selective Sensor based on 4-(2-Thiazolylazo)resorcinal

Abstract

4-(2-Thiazolylazo)resorcinol (TR) was used as a new compound to play the role of an excellent ion carrier in the fabrication of an Er(III) membrane electrode. The electrode shows a very good selectivity toward Er(III) ions over a wide variety of cations, including alkali, alkaline earth, transition, and heavy-metal ions. The proposed sensor exhibits a Nernstian behavior (with slope of 19.6 ± 0.6 mV per decade) over a wide concentration range (1.0 × 10^?6 to 1.0 × 10^?2 M). The detection limit of the sensor is 6.6 × 10^?7 M. It has a very short response time, in the whole concentration range (～10 s), and can be used for at least 12 weeks in the pH range of 2.8–9.3. The proposed sensor was successfully applied as an indicator electrode for the potentiometric titration of a Er(III) solution, with EDTA. It was also successfully applied to the F^? ion determination in some mouthwashing solutions.     

Original Potentiometric Ytterbium(III) PVC-Membrane Sensor Based on N1,N2-Bis-[1-(2-hydroxy-1,2-diphenyl)ethylidene]ethanedihydrazide

Abstract

In this work, we describe the construction, performance, and applications of an original ytterbium(III) sensor based on N¹,N²-bis-[1-(2-hydroxy-1,2-diphenyl)ethylidene]ethanedihydrazide (BHDEH), which acts as a suitable carrier. Because it has a low detection limit of 4.2 × 10^?7 M, the sensor response for the Yb(III) ion is Nernstian over a wide concentration range: four decades of concentration (1.0 × 10^?6 to 1.0 × 10^?2 M). The response time of the electrode is less than 10 s, it can be used in the pH range of 3.2–8.3, and its duration is at least 2 months without any considerable potential divergence. The sensor revealed very good selectivity for Yb(III) in the presence of several metal ions. To investigate the sensor analytical applicability, it was tested as an indicator electrode in the potentiometric titration of Yb(III) solution with standard EDTA solution. The proposed electrode was also used to determine fluoride ions in mouthwash.     

PPb Level Monitoring of Dy(III) Ions by a Highly Sensitive and Selective Dy(III) Sensor Based on a New Asymmetrical Schiff's Base

Abstract

A Dy(III) ion‐selective membrane sensor has been fabricated from polyvinyl chloride (PVC) matrix membrane containing a new asymmetrical Schiff's base [(E)‐N‐(2‐hydroxybenzylidene)benzohydraide] or BBH as a neutral carrier, sodium tetraphenyl borate (NaTPB) as an anionic excluder and nitrobenzene (NB) as a plasticizing solvent mediator. The membrane sensor displays linear potential response in the concentration range of 1.0×10^?2–1.0×10^?6 M of Dy(III). The electrode exhibits a nice Nernstian slope of 20.1±0.8 mV/decade in the pH range of 3.0–8.0. The sensor has a relatively short response time in whole concentration ranges (<20 s). The detection limit of the proposed sensor is 8.0×10^?7 M (～128 ng/mL), and it can be used over a period of six weeks. The selectivity of the proposed sensor with respect to other cations, (alkali, alkaline earth, transition and heavy metal ions) and especially lanthanid ions, is excellent. The practical utility of the sensor has been demonstrated by using it as an indicator electrode in the potentiometric titration of Dy(III) with EDTA.     

Determination of Dysprosium(III) Ion in Soil and Sediment Samples by an Original Potentiometric Dysprosium(III) Membrane Sensor

Abstract

A PVC membrane electrode for dysprosium(III) [Dy(III)] ions was constructed, having its basis on benzoxazoleguanidine (BG) as a suitable ionophore. The sensor presents a linear dynamic range of 1.0 × 10^?6–1.0 × 10^?1 M, with a Nernstian slope of 19.5 ± 0.4 mV decade^?1 and a detection limit of 4.7 × 10^?7 M. The response time is quick (less than 10 s). It can be used in the pH range of 3.3–8.4, and its duration is at least 2 mo without any considerable, noticeable potential divergence. The recommended sensor revealed comparatively good selectivity with respect to most alkali, alkaline earth, some transition, and heavy metal ions. It was successfully employed as an indicator electrode in the potentiometric titration of Dy(III) ions with EDTA. The membrane sensor also applied to the determination of concentration of Dy(III) ions in soil and sediment samples. Validation with certified reference materials (CRMs) was also carried out.     

Carbon nanotube composite PVC coated stainless steel disc electrode for detection of Ga(III)

This study demonstrates the application of the composite of multi-walled carbon nanotube polyvinylchloride (MWCNT-PVC) based on Bismarck Brown R for gallium sensor. MWCNT has a role to enhance the hydrophobicity of the membrane, which leads to a more stable potential signal. In addition by applying polypyrrol on the surface of this sensor a reduction in the drift of potential occurred and equilibrium potential was achieved faster. Compared to previous studies, using a stainless steel disc instead of a wire electrode causes to obtain an easily and more homogeneous coated electrode. The sensor shows a good Nernstian slope of 19.70?±?0.37?mV?decade^?1 in a wide linear range concentration of 1.0?×?10^?7 to 1.0?×?10^?2?M of Ga(NO₃)₃. The detection limit of this electrode was 7.7?×?10^?8?M of Ga(NO₃)₃. This proposed sensor is applicable in a wide pH range of 2 to 8. It has a short response time of about 8?s and has a good selectivity over twenty four various metal ions. The practical analytical utility of this electrode is demonstrated by measurement of Ga(III) in rock and different water samples.     

Novel Ytterbium(III) Selective Membrane Sensor Based on N‐(2‐Pyridyl)‐N′‐(2‐Methoxyphenyl)‐Thiourea as an Excellent Carrier and Its Application to Determination of Fluoride in Mouth Wash Preparation Samples

The construction, performance, and applications of a novel ytterbium(III) sensor based on N‐(2‐pyridyl)‐N′‐(2‐methoxyphenyl)‐thiourea (PMT), as an excellent carrier, in plasticized poly(vinyl chloride) PVC matrix, is described. The influences of membrane composition and pH on the potentiometric response of the sensor were investigated. The sensor exhibits a nice Nernstian response for Yb(III) ion over a wide concentration range of 4 decades of concentration (1.0×10^?6–1.0×10^?2 M), and a detection limit of 5.0×10^?7 M. The response time of the electrodes is between 8 and 10 s, depending on the concentration of ytterbium(III) ions. The proposed sensor can be used for about 8 weeks without any considerable divergence in potential. The sensor revealed very good selectivity for Yb(III) in the presence of several metal ions. The best performance was observed for the membrane containing; 30% PVC, 59% o‐nitrophenyloctyl ether (NPOE) as solvent mediator, 7% PMT, and 4% sodium tetraphenyl borate (NaTPB). It was successfully applied as indicator electrodes in the potentiometric titration of Yb(III) with EDTA and for the determination of fluoride ion in two mouth wash formulations. The proposed La(III) sensor was found to work well under laboratory conditions. It was also used as an indicator electrode in titration of a 1.0×10^?4 M of Yb(III) with a standard EDTA solution (1.0×10^?2 M). It was also used for determination of Yb(III) ion in Xenotime .     

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.     

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.     

Novel Potentiometric PVC‐Membrane and Coated Graphite Sensors for Lanthanum(III)

Preliminary theoretical studies revealed the selective complexation of bis (2‐mercaptoanil) diacetyl (BMDA) with La³⁺ over several alkali, alkaline earth and heavy metal ions. Thus, novel PVC‐based membrane (PBM) and coated graphite membrane (CGM) sensors for La(III) based on BMDA were prepared. The electrodes display Nernstian behavior over wide concentration ranges (i.e., 1.0×10^?5–1.0×10^?1 M for PBM and 1.0×10^?6–1.0×10^?1 M for CGM). The potential response of sensors was pH independent in the range of 4.0–8.0. The sensors possess satisfactory reproducibility, fast response time (<15 s), and specially excellent discriminating ability for La³⁺ ions with respect to most of the cations. The membrane sensor was used as an indicator electrode in potentiometric titration of lanthanum ions with EDTA. The coated graphite membrane electrode was applied in determination of fluoride ions in mouth wash preparations.     

Chromium(III) Ion Selective Electrode Based on Oxalic Acid Bis(Cyclohexylidene Hydrazide)

A poly(vinyl chloride) membrane sensor based on oxalic acid bis (cyclohexylidene hydrazide) as membrane carrier was prepared and investigated as a Cr(III)‐selective electrode. The electrode reveals a Nernstian behavior (slope 19.8±0.4 mV decade^?1) over a wide Cr(III) ion concentration range 1.0×10^?7–1.0×10^?2 mol dm^?3 with a very low limit of detection (i.e., down to 6.3×10^?8 mol dm^?3). The potentiometric response of the sensor is independent of the pH of the test solution in the pH range 1.7–6.5. The electrode possesses advantage of very fast response, relatively long lifetime and especially good selectivity to wide variety of other cations. The sensor was used as an indicator electrode, in the potentiometric titration of chromium ion and in the determination of Cr(III) in waste water and alloy samples.     

Novel Dy(III) Sensor Based on a New Bis‐Pyrrolidene Schiff's Base

In this work a dysprosium [Dy(III)]‐selective solvent polymeric membrane sensor based on N,N‐bis(pyrrolidene) benzne‐1,2‐diamine, poly(vinyl chloride)(PVC), the plasticizer benzylacetate (BA), and anionic site is described. This sensor responds to Dy(III) activity in a linear range from 1.0×10^?5 to 1.0×10^?1 M, with a slope of 20.6±0.2 mV per decade and a detection limit of 6.0×10^?6 M at the pH range of 3.5–8.0. It has a fast response time of<20 s in the entire concentration range, and can be used for at least 2 months without any considerable divergence in the electrode potentials. The proposed sensor revealed comparatively good selectivity with respect to common alkali, alkaline earth, transition and heavy metal ions. It was used as an indicator electrode in the potentiometric titration of fluoride ions and in determination of concentration of F ^– ions in some mouth washing solutions.     

Lanthanide Recognition: Determination of Thulium(III) Ions in Presence of Other Rare Earth Elements by a Thulium(III) Sensor Based on 4-Methyl-1,2-Bis(2-Pyridinecarboxamido)benzene as a Sensing Material

Abstract

In this research, a novel thulium(III) potentiometric membrane sensor based on 4-methyl-1,2-bis(2-pyridinecarboxamido) benzene (MPB) is described. The sensor exhibits a Nernstian response over a concentration range of 1.0 × 10^?7 M to 1.0 × 10^?1 M, with a detection limit of 9.0 × 10^?8 M. The best performance was achieved with a membrane composition of 30% PVC, 60% nitrobenzene (NB), 6% MPB, and 4% sodium tetraphenylborate (NaTPB). It was found that at the pH range of 3.6 to 9.0, the potential response of the sensor was not affected by the pH. Furthermore, the electrode presents satisfactory reproducibility, very fast response time (15 s), and relatively good discriminating ability for Tm(III) ions with respect to many common cations and lanthanide ions. The validation of the proposed electrode was tested by using Coal and Fuel Ash (FFA 1 Fly Ash) as a Certified Reference Material (CRM).     

Ruthenium(III) Schiff's Base Complex as Novel Chloride Selective Membrane Sensor

A novel chloride PVC‐based membrane sensor based on a ruthenium(III) Schiff's base complex, as an excellent neutral carrier, has been developed. The ruthenium complex, in combination with a ketonic plasticizer and a cationic additive led to ISEs with fundamental characteristics, such as slope sensitivity, short response times and selectivity coefficients, which were sufficient for practical applications. The sensor with composition of 30% PVC, 62% benzyl acetate, 5% ruthenium(III) Schiff's base complex and 3% hexadecyltrimethyl ammonium bromide displays near‐Nernstian behavior in a wide concentration range (1.0×10^?1–3.0×10^?6 M with slope of ?54.5±0.5) with a detection limit of 2.0×10^?6 M (71.0 ng per mL). The response of the electrode is independent on pH in the range of 4.0–10.0 and can it be used for at least ten weeks. The proposed electrode shows a very short response time (<20 s) in whole concentration range. The sensor displays high selectivity toward chloride ions over several organic and inorganic anions. It was successfully applied for the determination of chloride in serum samples. It was also used as an indicator electrode in the potentiometric titration of chloride ions with silver nitrate solution.     

A new PVC matrix membrane sensor for determination of praseodymium(III) ion based on bis(salicylaldehyde)thiocarbohydrazone as an ion carrier

The sufficient amounts of bis(salicylaldehyde) thiocarbohydrazone (STCH) as a lipophilic selective element (3%, w/w), sodium nitrobenzene (NB) as a plasticizer (64%, w/w), tetraphenyl borate (NaTPB) as an anionic additive (3%, w/w), and poly vinyl chloride (PVC) as a polymeric matrix (30%, w/w) was employed to form a PVC membrane of a new Pr³⁺ ions selective sensor to apply as an indicator electrode in analytical applications. The best electrode response was observed in the slope (19.5 ± 0.7 mV per decade) over a wide concentrations from lower (1.0 × 10^?6 mol L^–1) to higher (1.0 × 10^?2 mol L^–1) of Pr³⁺ ion solution with a detection limit of 8.5 × 10^–7 mol L^–1. This electrode showed the fast response time about 10 second for praseodymium ion concentration range of 1.0 × 10^–6 to 1.0 × 10^–2 mol L^–1, in the pH range of 2.3–7.9. The matched potential method was applied to study the selectivity of electrode toward Pr³⁺ ions in comparison with many common cations. The results showed the negligible disturbance of all other cations on the proposed praseodymium(III) electrode. The making sensor has been employed successfully as an indicator electrode in the potentiometric titration of praseodymium(III) solution with EDTA at pH 6.0. Moreover the applicability of the sensor was studied in determination of Pr³⁺ ion in mixtures of different ions.     

Samarium(III)-PVC-Membrane Sensor Based on Ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline

Abstract

2-Ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline (EED) was found to be a suitable neutral ionophore for the preparation of a highly selective samarium (Sm)(III) membrane sensor. Poly vinylchloride (PVC)–based membranes of EED with sodium tetraphenyl borate (NaTPB) as an anionic additive and dibutylphthalate (DBP), nitrobenzene (NB), and acetophenone (AP) as plasticizing solvent mediators were prepared and investigated as Sm(III) sensors. The sensor exhibited a Nernstian response over a concentration range of 1.0 × 10^?6 to 1.0 × 10^?2 M, with a detection limit of 5.0 × 10^?7 M. The best performance was achieved with a membrane composition of 30% PVC, 66% dibutyl phthalate (DBP), 2% EED, and 2% sodium tetraphenyl borate (NaTPB). It has a very short response time, in the whole concentration range (～10s), and can be used for at least 10 weeks. The proposed electrode shows a very good selectivity toward Sm(III) ions over a wide variety of cations, including alkali, alkaline earth, transition-metal, and heavy-metal ions. The sensor was applied to the determination of Sm ions in binary mixtures.     

Novel Bromide PVC‐Based Membrane Sensor Based on Iron(III)‐Salen

A novel bromide PVC‐based membrane sensor, based on iron(III)‐salen (IS) as an electroactive material, is successfully developed. The sensor possesses the advantages of low detection limit (6.0×10^?6), wide working concentration range (7.0×10^?6–1.0×10^?1 M), Nernstian behavior (slope of 59.0±0.5 mV per decade), low response time (<15 s), wide working pH range (3–9), and specially, high bromide selectivity over a wide variety of organic and inorganic anions, specially iodide, chloride, and hydroxide ions. The electrode was used in the direct potentiometric determination of hyoscine butylbromide, and as an indicator electrode in potentiometric titration of bromide ions with silver ions.     

A Samarium (III) Selective Electrode Based on Zirconium (IV) Boratophosphate

A samarium(III) selective potentiometric sensor has been prepared on the basis of polyvinyl chloride (PVC) membranes containing an ion exchanger (zirconium boratophosphate) as an electro-active material. The best performance was exhibited by a membrane having the following composition: zirconium boratophosphate (10%) and poly vinylchloride (90%). This membrane works well over a wide concentration range (from 1 × 10^?5 to 1 ? 10^?1 M) of Sm(III) ions with a Nernstian slope of 20.2 mV/decade. The response time of the sensor is 15 s, and the membrane can be used for more than six months with good reproducibility. Selectivity coefficients determined by the fixed interference method for a number of mono-, di-, and trivalent cations are reported. The sensor has also been used as an indicator electrode in the potentiometric titrations of samarium (III) ions with EDTA solution.     

Determination of Ytterbium(III) Ions in Soil and Sediment Samples by a New Polymeric Yb3+-PVC Membrane Sensor

Abstract

A polyvinyl chloride (PVC) membrane sensor for ytterbium(III) ions was prepared, based on 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene (BBT) as a membrane carrier. The sensor illustrates the following characteristics: a linear dynamic range of 1.0 × 10^?6 to 1.0 × 10^?2 M; a Nernstian slope of 19.7 ± 0.5 mV decade^?1; a detection limit of 4.4 × 10^?7 M; a response time of <10 s; and use for at least 2 months without any significant potential divergence in the pH range of 3.5–8.4. Moreover, the recommended selective sensor revealed a comparatively satisfactory selectivity regarding most of the alkali and alkaline earth ions and some of the transition-metal and heavy-metal ions. In fact, it was used as an indicator electrode in the Yb(III) potentiometric titration with ethylene diamine tetra-acetic acid (EDTA) and the determination of concentration of Yb(III) ions in soil and sediment samples.     

Thulium(III) Ions Monitoring by a Novel Thulium(III) Microelectrode Based on a S‐N Schiff Base

This study presents for the first time development of a highly selective and sensitive thulium(III) micro‐sensor. Theoretical calculations were conducted on a S‐N Schiff base [thiophene‐2‐carbaldehyde‐(7‐methyl‐1,3‐benzothiazol‐2‐yl) hydrazone] (TCMH) in order to obtain a clue about the tendency of TCMH to Tm(III) and some other metal ions. Then, TCMH was used as a membrane‐active component to prepare a Tm(III)‐selective polymeric membrane microelectrode. In line with the resulting data, the electrode exhibits a Nernstian response toward Tm(III) ions for a very wide concentration range (1.0×10^?11–4.0×10^?6 M) with a detection limit of 1.0×10^?11 (ca. 1.5 ppt) and a very fast response time in the whole concentration range (<5 s). In addition, the results showed that the certain microelectrode could be applied in the pH range of 4.0–11.0 with a usage of more than one month without any considerable potential divergence.     

A New Chromium(III) Microelectrode Based on Self‐Assembled Diethylenetriamminepentaacetic Acid‐Poly(fuchsin basic) Modified Electrode

A new selective, sensitive, and rapid response microelectrode for microamount chromium(III) determination was developed. For the electrode preparation, fuchsin basic was electropolymerized onto a carbon microdisk electrode, and then diethylenetriamminepentaacetic acid (DTPA) was self‐assembled on the electrode surface by the reaction between DTPA and poly(fuchsin basic). The determination conditions were optimized. The electrode showed a linear response to Cr³⁺ ions in the concentration range of 1.0×10^?6?1.0×10^?4 M and exhibits a super‐Nernstian slope of 32.5±0.4 mV per decade. The detection limit is 3.6×10^?7 M. The response time of the electrode is less than 10 s, and it can be used for at least 2 months with limited considerable divergences in its potentials. The proposed electrode was applied for monitoring the chromium ion level in wastewater of chromate industries.