scholarly journals Novel Potentiometric 2,6-Dichlorophenolindo-phenolate (DCPIP) Membrane-Based Sensors: Assessment of Their Input in the Determination of Total Phenolics and Ascorbic Acid in Beverages

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2058 ◽  
Author(s):  
Nada H. A. Elbehery ◽  
Abd El-Galil E. Amr ◽  
Ayman H. Kamel ◽  
Elsayed A. Elsayed ◽  
Saad S. M. Hassan
Keyword(s):  
Direct Determination ◽  
Inorganic Ions ◽  
Ion Association ◽  
Fast Response ◽  
Plasticized Pvc ◽  
Promising Tool ◽  
Total Antioxidant ◽  
Nernstian Slope ◽  
High Potential Stability

In this work, we demonstrated proof-of-concept for the use of ion-selective electrodes (ISEs) as a promising tool for the assessment of total antioxidant capacity (TAC). Novel membrane sensors for 2,6-dichlorophenolindophenolate (DCPIP) ions were prepared and characterized. The sensors membranes were based on the use of either CuII-neocuproin/2,6-dichlorophenolindo-phenolate ([Cu(Neocup)2][DCPIP]2) (sensor I), or methylene blue/2,6-dichlorophenolindophenolate (MB/DCPIP) (sensor II) ion association complexes in a plasticized PVC matrix. The sensors revealed significantly enhanced response towards DCPIP ions over the concentration range 5.13 × 10−5–1.0 × 10−2 and 5.15 × 10−5–1.0 × 10−2 M at pH 7 with detection limits of 6.3 and 9.2 µg/mL with near-Nernstian slope of −56.2 ± 1.7 and −51.6 ± 2 mV/decade for sensors I and II, respectively. The effects of plasticizers and various foreign common ions were also tested. The sensors showed enhanced selectivity towards DCPIP over many other phenolic and inorganic ions. Long life span, high potential stability, high reproducibility, and fast response were also observed. Method validation was also verified by measuring the detection limit, linearity range, accuracy, precision, repeatability and between-day-variability. The sensors were introduced for direct determination of TAC in fresh and canned juice samples collected from local markets. The obtained results agreed fairly well with the data obtained by the standard method.

scholarly journals Membrane Sensors for the Selective Determination of Donepezil Hydrochloride

2010 ◽  
Vol 93 (2) ◽  
pp. 549-555 ◽  
Author(s):  
Gamal Abdel Hafiz Mostafa ◽  
Mohamed Hefnawy ◽  
Abdulrahman Al-Majed
Keyword(s):  
Direct Determination ◽  
Pharmaceutical Preparations ◽  
Ion Association ◽  
Phosphomolybdic Acid ◽  
Hplc Method ◽  
Pvc Membrane ◽  
Selective Determination ◽  
Response Characteristics ◽  
Sodium Tetraphenyl Borate

Abstract The construction and electrochemical response characteristics of polyvinylchloride (PVC) membrane sensors for donepezil HCl (DP) are described. The sensing membranes incorporated ion-association complexes of DP cation and sodium tetraphenyl borate (sensor 1), phosphomolybdic acid (sensor 2), or phosphotungstic acid (sensor 3) as electroactive materials. The sensors displayed a fast, stable, and near-Nernstian response over a relatively wide DP concentration range (1 102 to 1 106 M), with cationic slopes of 53.0, 54.0, and 51.0 mV/ concentration decade over a pH range of 4.0 to 8.0. The sensors showed good discrimination of DP from several inorganic and organic compounds. The direct determination of 2.54000.0 g/mL DP showed average recoveries of 99.0, 99.5, and 98.5, and mean RSDs of 1.6, 1.5, and 1.7 at 100.0 g/mL for sensors 1, 2, and 3, respectively. The proposed sensors have been applied for direct determination of DP in two pharmaceutical preparations. The results obtained for determination of DP in tablets using the proposed sensors compared favorably with those obtained using an HPLC method. The sensors have been used as indicator electrodes for potentiometric titration of DP.

scholarly journals Determination of Nd3+Ions in Solution Samples by a Coated Wire Ion-Selective Sensor

2012 ◽  
Vol 9 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Hassan Ali Zamani
Keyword(s):  
High Selectivity ◽  
Water Solution ◽  
Fast Response ◽  
Indicator Electrode ◽  
Coated Wire ◽  
Nernstian Slope ◽  
Ph Range ◽  
Coated Wire Electrode ◽  
Selective Sensor

A new coated wire electrode (CWE) using 5-(methylsulfanyl)-3-phenyl-1H-1,2,4-triazole (MPT) as an ionophore has been developed as a neodymium ion-selective sensor. The sensor exhibits Nernstian response for the Nd3+ions in the concentration range of 1.0×10−6-1.0×10−2M with detection limit of 3.7×10−7M. It displays a Nernstian slope of 20.2±0.2 mV/decade in the pH range of 2.7–8.1. The proposed sensor also exhibits a fast response time of ∼5 s. The sensor revealed high selectivity with respect to all common alkali, alkaline earth, transition and heavy metal ions, including members of the lanthanide family other than Nd3+. The electrode was used as an indicator electrode in the potentiometric titration of Nd(III) ions with EDTA. The electrode was also employed for the determination of the Nd3+ions concentration in water solution samples.

Modified Screen-Printed Ion Selective Electrodes for Potentiometric Determination of Sodium Dodecylsulfate in Different Samples

2015 ◽  
Vol 98 (1) ◽  
pp. 116-123 ◽  
Author(s):  
Tamer Awad Ali ◽  
Gehad G Mohamed
Keyword(s):  
Response Times ◽  
Inorganic Compounds ◽  
Cetylpyridinium Chloride ◽  
Sodium Dodecylsulfate ◽  
Direct Determination ◽  
Pharmaceutical Preparations ◽  
Ion Association ◽  
Potentiometric Determination ◽  
Screen Printed

Abstract Fabrication and general performance characteristics of novel screen-printed sensors for potentiometric determination of sodium dodecylsulfate (SDS) are described. The sensors are based on the use of ion-association complexes of SDS with cetylpyridinium chloride (electrode I) and cetyltrimethylammonium bromide (electrode II) as exchange sites in a screen-printed electrode matrix. Electrodes (I) and (II) show fast, stable, and near-Nernstian response for the mono-charge anion of SDS over the concentration range of1 × 10–2 – 5.8 × 10–7 and 1 × 10–2 – 6.3 × 10–7 mol/L at 25°C and the pH range of 2.0–9.0 and 2.0–8.0 with anionic slope of 57.32 ± 0.81 and 56.58 ± 0.65 mV/decade, respectively. Electrodes (I) and (II) have lower LODs of 5.8 × 10–7 and 6.3 × 10–7 mol/L and response times of about 8 and 13 s, respectively. Shelf life of5 months for both electrodes is adequate. Selectivity coefficients of SDS related to a number of interfering cations, and some inorganic compounds were investigated. There were negligible interferences causedby most of the investigated species. The direct determination of 0.10–13.50 mg of SDS by electrodes (I) and (II) shows average recoveries of 99.96 and 99.85%, and mean RSDs of 0.83 and 1.04%, respectively. In the present investigation, both electrodes were used successfully as end point indicators for determination of SDS in pure pharmaceutical preparations and real spiked water samples. The results obtained using the proposed sensors to determine SDS in solution compared favorably with those obtained by thestandard addition method.

Iodide Ion Sensor for Indirect Determination of As (III) in Water

2010 ◽  
Vol 117 ◽  
pp. 93-98
Author(s):  
A. Nyachhyon ◽  
A.P. Yadav ◽  
Krishna Manandhar ◽  
Raja Ram Pradhananga
Keyword(s):  
Polycrystalline Material ◽  
Low Cost ◽  
Direct Determination ◽  
Selectivity Coefficient ◽  
Indirect Determination ◽  
Iodide Ion ◽  
Silver Sulphide ◽  
Nernstian Slope ◽  
Co Precipitation

A simple, low cost and portable iodide sensor for the indirect determination of As(III) has been developed from the polycrystalline material obtained by co-precipitation of silver sulphide and silver iodide from aqueous solution. The Ag2S-AgI sensor was found to behave well up to the iodide concentration of 1×10-6 M with a Nernstian slope 57.5 mV per decade change in concentration. The selectivity coefficient of sensor containing iodide ion in the presence of Br- and Cl- ions was found to be 1.77 × 10-2 and 7.94 × 10-3, respectively indicating that these ions do not interfere in the response of iodide sensor to iodide ion. The electrode was successfully used for the direct determination of iodide and indirect determination of As(III) by titrating with cerric ammonium sulphate at pH 2. The results obtained from this method are comparable to the existing methods for the estimation of As(III).

scholarly journals PVC-Membrane Potentiometric Electrochemical Sensor Based on 2-(4-Oxopentan-2-ylideneamino)isoindoline-1,3-dione for Selective Determination of Holmium(III)

2011 ◽  
Vol 8 (s1) ◽  
pp. S97-S104 ◽  
Author(s):  
Hassan Ali Zamani
Keyword(s):  
Heavy Metal Ions ◽  
Alkaline Earth ◽  
Fast Response ◽  
Pvc Membrane ◽  
Indicator Electrode ◽  
Selective Determination ◽  
Nernstian Slope ◽  
Neutral Ionophore ◽  
Ph Range

2-(4-Oxopentan-2-ylideneamino) isoindoline-1,3-dione (OID) was found to be a suitable neutral ionophore in the fabrication of a highly selective Ho3+membrane sensor. The electrode has a near-Nernstian slope of 19.6±0.5 mV per decade with a wide concentration range between 1.0×10-6and 1.0×10-2mol/L in the pH range of 3.5–8.8, having a fast response time (∼5 s) and a detection limit of 5.8×10-7mol/L. This electrode presented very good selectivity and sensitivity towards the Ho3+ions over a wide variety of cations, including alkali, alkaline earth, transition and heavy metal ions. The practical utility of the electrode has been demonstrated by its use as an indicator electrode for the potentiometric titration of a Ho3+solution with EDTA and for the determination of Ho3+ions concentration in mixtures of two and three different ions.

scholarly journals Analytical applications of electrode sensitive to labetalol in pharmaceuticals

2003 ◽  
Vol 1 (3) ◽  
pp. 242-259 ◽  
Author(s):  
Ewa Gorodkiewicz ◽  
Paweł Falkowski ◽  
Anna Sankiewicz ◽  
Zbigniew Figaszewski
Keyword(s):  
Liquid Membrane ◽  
Inorganic Ions ◽  
Structural Similarity ◽  
Protonated Form ◽  
Direct Potentiometry ◽  
Analytical Properties ◽  
Nernstian Slope ◽  
Ph Range ◽  
Influence Of Ph

AbstractThe analytical properties of an ion-selective electrode sensitive to labetalol with a liquid membrane, based on ion-pair complexes with sodium tetraphenylborate (TPB-Na+) are described. The studied electrode can be used for the determination of labetalol hydrochloride as a protonated form of labetalol in pharmaceuticals. The calibration curve, e.g. EMF=f(pCLabHCl) is linear in the range from 10−5 to 10−2 mol L−1 with a correlation coefficient of 0.9992 and slope of 61.13 mV/decade, which is close to the Nernstian slope. The detection limit of the examined electrode is 7.20×10−6 mol L−1. The influence of pH of the tested solutions on the formulation of the electrode is not as considerable since the electrode works correctly in the pH range 3.0–8.0. The main attributes of the developed electrode are: stability, good reproducibility of EMF and short response time, close to 30 seconds depending on labetalol concentration in the solution. The electrode shows good selectivity for many inorganic ions. The selectivity for drug cations is weaker due to the structural similarity of the interfering cations to labetalol. The results of labetalol determination using direct potentiometry in drugs such as Pressocard (Polpharma) and Trandate (GlaxoWellcome) were compatible with the quantity of labetalol declared by the manufacturer, and with parallel UV spectrophotometric and HPLC determinations.

scholarly journals Fabrication and evaluation of potentiometric sensors of an anticancer drug (Gemcitabine)

2020 ◽  
Vol 11 (1) ◽  
pp. 21-29 ◽  
Author(s):  
Iyad Darweesh Al-Kashef ◽  
Salman Mostafa Saadeh ◽  
Khalid Ibrahim Abed Almonem ◽  
Nasser Mohammed Abu Ghalwa ◽  
Hazem Mohammed Abu Shawish
Keyword(s):  
Anticancer Drug ◽  
Limit Of Detection ◽  
Inorganic Ions ◽  
Potentiometric Sensors ◽  
Pvc Membrane ◽  
Carbon Paste ◽  
Curve Method ◽  
Nernstian Slope ◽  
Ph Range

Accurate, rapid and inexpensive determination of gemcitabine, an anticancer drug, is of high interest. This manuscript describes the use of potentiometric sensors as a basis for this work given their known attractive characteristics that meet our needs. Potentiometric sensors were comprised of carbon paste S1, coated wire S2 and PVC membrane S3, of gemcitabine (an anticancer drug) were fabricated, studied and evaluated. The calibration plots for these electrodes showed a Nernstian slope of 58.4±0.3, 59.5±0.3 and 58.3±0.3 mV per decade with the limit of detection: 6.50×10-5, 7.20×10-5 and 4.60×10-5 for sensors S1, S2 and S3, respectively. The electrodes have a short and stable response time of ~5 seconds and good reproducibility in a pH range of 2.5-9.5. The present sensors show distinct selectivity toward the drug ion in comparison to several inorganic ions, sugars, amino acids and some common drug excipients. Gemcitabine was determined successfully in ampoules and urine using these sensors by the calibration curve method.

Direct Determination of Inorganic Ions at Sub-ppb Levels by Ion Chromatography Using Water as a Mobile Phase

1995 ◽  
Vol 67 (20) ◽  
pp. 3713-3716 ◽  
Author(s):  
Wenzhi. Hu ◽  
Mamoru. Tominaga ◽  
Hiroaki. Tao ◽  
Akihide. Itoh ◽  
Tomonari. Umemura ◽  
...  
Keyword(s):  
Ion Chromatography ◽  
Mobile Phase ◽  
Direct Determination ◽  
Inorganic Ions

scholarly journals Novel Validated Analytical Method Based on Potentiometric Transduction for the Determination of Citicoline Psychostimulant/Nootropic Agent

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3512
Author(s):  
Ayman H. Kamel ◽  
Abd El-Galil E. Amr ◽  
Hoda R. Galal ◽  
Abdulrahman A. Almehizia
Keyword(s):  
High Performance ◽  
Ion Association ◽  
Pharmaceutical Formulations ◽  
Hplc Method ◽  
Polymeric Membranes ◽  
Nootropic Agent ◽  
High Potential Stability ◽  
First Time ◽  
Potential Stability

Herein, a novel validated potentiometric method is presented for the first time for citicoline determination. The method is based on measuring the potential using new constructed citicoline electrodes. The electrodes are based on the use of citicolinium/phosphomolybdate [Cit]2[PM] (sensor I) and citicolinium/tetraphenylborate [Cit][TPB] (sensor II) ion association complexes. These sensory materials were dispersed in plasticized polyvinyl chloride (PVC) polymeric membranes. The sensors revealed a Nernstian response with the slopes 55.9 ± 1.8(r2 = 0.9994) and 51.8 ± 0.9 (r2 = 0.9991) mV/decade over a linearity range of 6.3 × 10−6–1.0 × 10−3 and 1.0 × 10−5–1.0 × 10−3 M and detection limits of 3.16 × 10−6 and 7.1 × 10−6 M for sensors I and II, respectively. To ensure the existence of monovalent citicoline, all measurements were performed in 50 mM acetate buffer at pH 3.5. All presented electrodes showed good performance characteristics such as rapid response, good selectivity, high potential-stability and long life-span. Method verification and validation in terms of response linearity, quantification limit, accuracy, bias, trueness, robustness, within-day variability and between-days variability were evaluated. The method was introduced for citicoline determination in different pharmaceutical formulations and compared with the standard high performance liquid chromatography (HPLC) method.

Effect of Heating Treatment of Fresh Rice Bran on Stabilization

2012 ◽  
Vol 602-604 ◽  
pp. 1200-1205
Author(s):  
Zhu Gong ◽  
Guo Ping Yu ◽  
Chao Ran Dou ◽  
Man Xu Xu
Keyword(s):  
Heat Treatment ◽  
Rice Bran ◽  
Peroxidase Activity ◽  
Direct Determination ◽  
Material Resources ◽  
Total Antioxidant ◽  
Heating Treatment ◽  
The Stability ◽  
First Time

In the research of rice bran stabilization, most of the literature only study the lipase which is explained by the changes in free fatty acids in the storage experiment or peroxidase activity. It leads results not comprehensive, extends the experiment time, increases the experimental difficulty and wastes of manpower and material resources. For the first time, the effect of heat treatment on fresh rice bran stability is examined in terms of direct determination of water content, lipase activity, peroxidase activity and total antioxidant capacity. The optimal condition is that 120 degrees for 22 min. The results show that the heat treatment can reduce the enzyme activity of rice bran to improve the stability of rice bran.

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