Potentiometric Sensor For Selective Determination Research Articles

Novel fabricated potentiometric sensors for selective determination of carbinoxamine with different greenness evaluation perspectives

Electrochemical sensors, such as ion-selective electrodes (ISEs) is one of the promising green analytical techniques with significant advances that opens up new frontiers of its application. In this contribution, we developed and validated novel potentiometric sensing method for selective monitoring of carbinoxamine maleate (CRX) in presence of the co-formulated drugs. A comparative potentiometric study was employed using a dual design of ISEs; a classical liquid inner-contact and solid-contact sensors. Herein, a full investigation of the opportunities and challenges offered by the two ISEs assemblies and configurations were discussed. Taking into consideration the impressive added values of solid-contact ISEsover the conventional ones, including: being eco-friendly, real-time analyzers, portable, disposal, maintenance-free, easily miniaturized, and compatible with microfabrication technologies. The backbone of the solid contact electrode is the incorporation of ionophore (2-hydroxypropyl-β-cyclodextrin) as supramolecular element and a network of multi-walled carbon nanotubes as ion-to-electron transducer in a single-piece nanocomposite membrane. Besides, the fabrication of solid-state ISEs was performed via simple one-step drop casting of the ion sensing mixture on surface of microfabricated electrode.Furthermore, the morphological and structural features of the obtained membrane were characterized using Raman spectroscopy and scanning electron microscopy (SEM) techniques. The suggested sensors were successfully applied for quantitation of CRX in its pure and dosage form. Performances of fabricated sensors were assessed as per IUPAC recommendations. The outcomes of the proposed method were statistically benchmarked to the official approach, where no significant difference was found. Moreover, a comprehensive greenness evaluation of the investigated method was performed via various green-metrics, namely, GAM, Eco-Scale, GAPI and AGREE algorithm which is utilized 12 principles of green analytical chemistry. Finally, studying the whiteness degree of the established method was conducted using the recently introduced RGB12 model.

Novel coated wire potentiometric sensor for selective determination of Mn(II) ions in various authentic samples

Novel coated wire potentiometric sensor for selective determination of Mn(II) ions in various authentic samples

Carbon thick sheet potentiometric sensor for selective determination of silver ions in X-ray photographic film

Innovative screen-printed electrode (SPE) based on Alizarin Red S (ARS) for Ag (I) ion determination was developed. The ionophore content was varied and optimized which indicated that the ink incorporating 30 mg of Alizarin Red S reflects the best experimental performance exhibiting monovalent Nernstian slope value of 59.95 mV decade−1 over a considerable spacious concentration range from 5.0 × 10−7 to 1.0 × 10−2 mol L − 1 with a lower detection limit value of 5.0 × 10−7 mol L − 1. Additionally, the developed sensor stable for more than 112 days without any significant drift in potential exhibited a fast response time (7 s). The interaction between Ag (I) ions and ARS ionophore at the electrode surface was investigated and elucidated using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and FTIR spectra measurement. The proposed sensor achieved constant potentiometric response in pH range of 4–8 and thermally stable to 50 ͦ C. The developed sensor indicates discriminating capability toward Ag (I) ions with regard to most common transition metal ions. The new developed sensor used for determination of Ag (I) ion in x-ray photographic film and can be applied as indicator electrode in precipitation titrations. Furthermore, the method was validated according to IUPAC recommendation parameters.

Designing of a Novel Potentiometric Sensor for Selective Determination of Chromium (III) Ion in Real Samples

The purpose of this work is to design and develop a sensitive and selective electrochemical sensor for quantification analysis of Chromium (III) in different samples, such as drinking water, seawater, pharmaceutical products, soil and food.Chromium is an essential metal in small amounts while toxic in larger quantities. Recommended chromium intakes are provided in the dietary reference intakes (DRIs) developed by the institute of Medicine of the National Academy of science. Serum chromium levels normally range from less than 0.05 up to 0.5 micrograms/milliliter (mcg/mL) in humans. Chromium blood test is performed in laboratories to diagnose chromium poisoning or deficiency. For medical and environmental reasons, it is of great importance to determine how much of this metal ion is present in such media. To date, many Cr (III) selective electrodes with PVC membrane, based on various ionophores, have been introduced; however, these sensors suffer from the disadvantages of significant interferences from other cations, deviation from Nernstian behavior, small linear range and narrow pH range of operation [1].The main goal of this project is to fabricate a potentiometric sensor which is selective towards Cr (III) ions, and does not have the disadvantages of the above-mentioned Cr (III)-selective membrane sensors. In this regards, TiO2/FTO glasses modified with glyoxal bis (2-hydroxyanil) (GBHA) as the ionophore (analyte recognition part) [2] were prepared, and investigated as Cr (III)-selective electrodes.The first component of the proposed potentiometric sensor is the working electrode. TiO2/FTO glass substrate was chosen as the working electrode material. The TiO2 film was prepared following a standard method described elsewhere [3]. The morphology of the TiO2 films was investigated by scanning electron microscopy (SEM) to assure that the TiO2 particles formed a homogenous porous film and to monitor film thickness. The TiO2/FTO substrates were subsequently modified with the ionophore of interest (GBHA) and the potentials of the varying concentration solutions of Cr (III) were read form the voltmeter upon increasing the concentration of the test solutions. We are also planning to apply other substrates as the working electrode, such as gold electrodes using thiol chemistry to chemically immobilise the ionophores.Our results demonstrated that the proposed potentiometric sensor exhibits a Nernstian response for Cr (III) ions over a wide concentration range (1.0×10-7 M-1.0×10-2 M); it also showed a fast response time, and its potential response remained unaffected of PH in a wide range.Moreover, the performance of the sensor is discussed in terms of stability, response time, and possible interferences from other ions. The proposed sensor is to be tested for the analysis of some water samples and food materials for the determination of Cr (III) ions. The fabricated sensor offered simplicity, rapidity, and reliability as an analytical tool.The second component of the constructed Cr (III)-selective potentiometric sensor is the ionophore or the ion receptor (GBHA), which is responsible for interacting with the Cr (III) ions and therefore producing a signal (voltage). We tried to optimize the ways to immobilize the ionophore on the working electrode, using different linkers, in order to increase the stability as well as the life time of our fabricated sensor. Distribution of the ion receptor on the surface is important to prevent aggregation prior or upon binding. In addition, various surfaces’ chemistry will be explored to prevent physical adsorption of other components of the samples.

A Novel Potentiometric Sensor for Selective Determination of Dodecyl(2-Hydroxyethyl)-Dimethylammonium Bromide Surfactant in Environmental Polluted Samples

A Novel Potentiometric Sensor for Selective Determination of Dodecyl(2-Hydroxyethyl)-Dimethylammonium Bromide Surfactant in Environmental Polluted Samples

Zn(II) complex-based potentiometric sensors for selective determination of nitrate anion

Polymeric membranes containing new Zn(II) complexes as anion carriers were prepared for determination of nitrate anion present in water samples. Two Zn(II) complexes coordinated by neutral tetradentate ligands, N,N′-ethylene-bis( N-methyl-( S)-alanine methylamide) and N,N′-ethylene-bis( N-methyl-( S)-alanine dimethylamide), worked well as anion-selective carriers, while common phthalocyanine Zn(II) complex rarely responded to any anions. The combination of these new Zn(II) complexes with dioctylsebacate as a plasticizer particularly offered high sensing selectivity for nitrate anion. They exhibited near-Nernstian slopes in the wide linear concentration range of 5.0 × 10 −5 to 1.0 × 10 −1 M, and operated well in the wide pH range from 4 to 11 with the response time of less than 25 s. The potentiometric selectivity coefficients were evaluated using the fixed interference method, indicating that the two Zn(II) complexes exhibited better selectivity for nitrate anion with respect to a wide variety of inorganic anions. Although chloride anion worked as an interfering species at a concentration higher than 1.0 × 10 −3 M, the new Zn(II) complex-based sensors were applicable in determination of the nitrate anion after adding silver sulfate to remove the chloride anion.

A novel potentiometric sensor for selective determination of theophylline: Theoretical and practical investigations

A novel theophylline potentiometric sensor is prepared, characterized and used in pharmaceutical analysis. The sensor is based on a PVC membrane containing dibutyl phthalate as plasticizer, 2,6-bis(phenyl)-4(phenyl)3H-thiopyran (PPT) as ionophore and oleic acid (HOA) as additive. A linear response in the range of 1.0 × 10 −6 to 1.0 × 10 −2 M of theophylline with a slope 54.5 ± 0.4 mV per decade was established. The optimum pH range was 5.3–7.3 and the lower detection limit was 5.5 × 10 −7 M of theophylline. The electrode displays a good selectivity for theophylline with respect to a large number of common foreign inorganic and organic species, amino acids and drugs. The membrane sensor was successfully applied to the determination of theophylline in its tablets. A theoretical study based on the optimum angle and distance between theophylline and PPT molecules was conducted. These investigations were carried out based on ab initio calculations, to estimate the pair wise interaction energy between the two molecules.

Molecular Recognition of Dihydroxybenzenes by Macrocyclic Polyamines in Langmuir Films and PVC Matrix

Lipophilic polyamines 1 and 2 form stable monolayers at the air–water interface. The shapes of the isotherms show a strong pH-dependence due to different stages of polyamine protonation. For all isomers of dihydroxybenzene the strong interaction with 1 and 2 can be observed at pH 4, 6, and 8. Polyamines 1and 2 in the PVC liquid membrane act as the sensory element of the potentiometric sensor for selective determination of catechol in the presence of other isomers of dihydroxybenzenes.