scholarly journals Liquid Contact-Selective Potentiometric Sensor Based on Imprinted Polymeric Beads Towards 17β-Estradiol Determination

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1506
Author(s):  
Ayman H. Kamel ◽  
Abd El-Galil E. Amr ◽  
Hoda R. Galal ◽  
Elsayed A. Elsayed ◽  
Ahmed I. Al-Sayady
Keyword(s):  
Limit Of Detection ◽  
Biological Fluids ◽  
Pharmaceutical Preparations ◽  
Sample Pretreatment ◽  
Fast Response ◽  
Ion Selective Electrodes ◽  
Local Market ◽  
Buffer Solution ◽  
Wide Range ◽  
17Β Estradiol

Novel potentiometric devices “ion-selective electrodes (ISEs)” were designed and characterized for the detection of 17β-estradiol (EST) hormone. The selective membranes were based on the use of man-tailored biomimics (i.e., molecularly imprinted polymers (MIPs)) as recognition ionophores. The synthesized MIPs include a functional monomer (methacrylic acid (MAA)) and a cross-linker (ethylene glycol dimethacrylic acid (EGDMA)) in their preparation. Changes in the membrane potential induced by the dissociated 17β-estradiol were investigated in 50 mM CO32−/HCO3− buffer solution at pH 10.5. The ion-selective electrodes (ISEs) exhibited fast response and good sensitivity towards 17β-estradiol with a limit of detection 1.5 µM over a linear range starts from 2.5 µM with an anionic response of 61.2 ± 1.2 mV/decade. The selectivity pattern of the proposed ISEs was also evaluated and revealed an enhanced selectivity towards EST over several phenolic compounds. Advantages revealed by the presented sensor (i.e., wide range of assay, enhanced accuracy and precision, low limit of detection, good selectivity, long-term potential stability, rapid response and long life-span and absence of any sample pretreatment steps) suggest its use in routine quality control/quality assurance tests. They were successfully applied to estradiol determination in biological fluids and in different pharmaceutical preparations collected from the local market.

scholarly journals Determination of Gliclazide in Pharmaceutical Preparations by Capillary Gas Chromatography with Cool On-Column Injection and Elimination of the Matrix Effect

2001 ◽  
Vol 84 (6) ◽  
pp. 1695-1702 ◽  
Author(s):  
Jan Krzek ◽  
Janusz Czekaj ◽  
Maria Moniczewska ◽  
Włodzimierz Rzeszutko
Keyword(s):  
Gas Chromatography ◽  
Capillary Gas Chromatography ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Pharmaceutical Preparations ◽  
Fused Silica ◽  
Uv Spectrophotometry ◽  
Relative Standard ◽  
Wide Range ◽  
The Matrix

Abstract Conditions were established for the identification and quantitation of gliclazide in pharmaceutical preparations by capillary gas chromatography with flame ionization detection and cool on-column injection. Gliclazide was extracted with methanol and, after filtration, assayed on a (25 m × 0.25 mm id, 0.2 μm film thickness) CP-WAX 58 (FFAP)–CB WCOT fused silica column. Because the available preparations were of various origins and, therefore, could differ in auxiliary substances and their qualitative parameters, the influence of the matrix constituents on the analytical results was taken into account. Good separation conditions were established for the developed method. The retention time of gliclazide is about 36 min and differs from the retention times of the internal standard (approximately 29 min) and additional peaks present in chromatograms (20–26 min), which were assigned to matrix constituents. The recoveries of gliclozide were high and reached 96.5%. The developed method is characterized by selectivity and precision (relative standard deviation 0.38–1.26%), a wide range of linearity (0.1–10.0 mg/mL), and a limit of detection of 30 ng. In addition, the results of chromatographic analyses calculated in 3 ways were compared with those obtained by UV spectrophotometry. The suggested technique of cool on-column injection, in contrast with split-splitless injection (used in preliminary investigations), reduces to a minimum the possibility of thermal decomposition of gliclazide.

scholarly journals Spectrophotometric and RP-HPLC Methods for Determining Cefotaxime Sodium in Pharmaceutical Preparations

2020 ◽  
Vol 32 (6) ◽  
pp. 1314-1320
Author(s):  
Lamya A. Sarsam ◽  
Salim A. Mohammed ◽  
Sahar A. Fathe
Keyword(s):  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Pharmaceutical Preparations ◽  
Molar Absorptivity ◽  
Hplc Method ◽  
Buffer Solution ◽  
Limit Of Quantification ◽  
Rp Hplc ◽  
Relative Standard

A rapid, simple and sensitive spectrophotometric and RP-HPLC methods have been developed for the quantitative determination of cefotaxime-Na in both pure and dosage forms. The spectrophotometric method was based on diazotization of cefotaxime-Na and then coupling with 8-hydroxyquinoline in an alkaline medium. The resulting azo dye exhibited maximum absorption at 551 nm with a molar absorptivity of 0.597 × 104 L mol-1 cm-1. Beer′s law was obeyed over the range 10-700 μg/25 mL (i.e. 0.4-28.0 ppm) with an excellent determination coefficient (R2 = 0.9993). The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.0194 and 0.3765 μg mL-1, respectively. The recoveries were obtained in the range 97.3-102.5% and the relative standard deviation (RSD) was better than ± 1.56. The HPLC method has been developed for the determination of cefotaxime-Na. The analysis were carried out on a C18 column and a mobile phase composed of acetonitrile and phosphate buffer solution (0.024M KH2PO4 and 0.01M H3PO4) at pH 3.5 in the ratio of 60:40 (v:v), with a flow rate of 1.0 mL min-1 and UV detection at 258 nm. The proposed method showed good linearity (in a range of concentration 1.0-200 μg mL-1. The recovery percent and a relative standard deviations were found in the range 96 to 104.8% and ± 0.017 to ± 0.031%, respectively. Both methods were applied successfully to the assay of cefotaxime-Na in commercial injection preparations.

scholarly journals Determination of Vitamin B6 (pyridoxine hydrochloride) in Pharmaceutical Preparations Using High Performance Liquid Chromatography

2019 ◽  
Vol 60 (5) ◽  
pp. 943-951
Author(s):  
Hana Sh. Mahmood ◽  
Rabah R. Ahmad
Keyword(s):  
Vitamin B6 ◽  
High Performance ◽  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
High Performance Liquid Chromatographic ◽  
Pyridoxine Hydrochloride ◽  
Buffer Solution ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Determination of vitamin B6 (pyridoxine hydrochloride) was described using high performance liquid chromatographic method. The analysis was achieved by cosmos IL 5C18-MS-II column (250 mm x 4.6 mm i. d., 5µm particle size) at room temperature. The mobile phase used was Acetonitrile, buffer solution (Citric acid, Na2HPO4 pH4) buffer solution in the ratio (70:30) (V: V). the flow rate was set to 1.25 mL.min-1 and the retention time 1.82 min with UV-detection at 282 nm. Beer's law was obeyed over the concentration range 10-1250 µg.mL-1. The method was accurate (relative error % less than 0.05%), precise (RSD better than ±1.05%), average recovery 100.05%, with a limit of detection and quantification of 2.2μg.ml−1, and 7.34μg.mL−1 respectively. The proposed method was successfully applied to determine the pyridoxine hydrochloride in pharmaceutical preparations in both forms of tablet and injection

scholarly journals Electrochemical Polymerised Graphene Paste Electrode and Application to Catechol Sensing

2019 ◽  
Vol 13 (1) ◽  
pp. 81-87 ◽  
Author(s):  
Jamballi G. Manjunatha
Keyword(s):  
Modified Electrode ◽  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Sample Pretreatment ◽  
Differential Pulse ◽  
Buffer Solution ◽  
Solution Ph ◽  
Graphene Paste Electrode ◽  
Paste Electrode

Objective: To build up an advantageous strategy for sensitive determination of catechol (CC), a poly (proline) modified graphene paste electrode (PPMGPE) was fabricated and used as a voltammetric sensor for the determination of CC. Methods: The performance of the modified electrode was studied using cyclic voltammetric (CV) and differential pulse voltammetric method (DPV). The modified electrode was characterized by CV and DPV. The surface of the modified electrode was examined by FESEM. The electrochemical behavior of CC in phosphate buffer solution (pH 7.5) was inspected using bare graphene paste electrode (BGPE) and PPMGPE. Results & Conclusion: The PPMGPE shows a lower limit of detection, calculated to be 8.7×10–7mol L−1 (S/N=3). This modified electrode was applied successfully for the determination of CC in water samples without applying any sample pretreatment.

scholarly journals A Sensitive FRET Biosensor Based on Carbon Dots-Modified Nanoporous Membrane for 8-hydroxy-2′-Deoxyguanosine (8-OHdG) Detection with Au@ZIF-8 Nanoparticles as Signal Quenchers

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 2044
Author(s):  
Weiwei Ye ◽  
Yu Zhang ◽  
Wei Hu ◽  
Liwen Wang ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Limit Of Detection ◽  
Biological Fluids ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Sample Pretreatment ◽  
Alumina Membrane ◽  
Zeolitic Imidazolate Framework ◽  
Quenching Efficiency ◽  
Oxidation Damage

A sensitive fluorescence resonance energy transfer (FRET) biosensor is proposed to detect 8-hydroxy-2′-deoxyguanosine (8-OHdG), which is a typical DNA oxidation damage product excreted in human urine. The FRET biosensor was based on carbon dots (CDs)-modified nanoporous alumina membrane with CDs as fluorescence donors. Gold nanoparticles were encapsulated in zeolitic imidazolate framework-8 to form Au@ZIF-8 nanoparticles as signal quenchers. CDs and Au@ZIF-8 nanoparticles were biofunctionalized by 8-OHdG antibody. The capture of 8-OHdG on the membrane substrates can bring Au@ZIF-8 nanoparticles closely to CDs. With 350 nm excitation, the fluorescence of CDs was quenched by Au@ZIF-8 nanoparticles and FRET effect occurred. The quenching efficiency was analyzed. The limit of detection (LOD) was 0.31 nM. Interference experiments of the FRET biosensor showed good specificity for 8-OHdG detection. The biosensor could detect urinary 8-OHdG sensitively and selectively with simple sample pretreatment processes. It shows applicability for detecting biomarkers of DNA damage in urine or other biological fluids.

scholarly journals A New Validated Potentiometric Method for Sulfite Assay in Beverages Using Cobalt(II) Phthalocyanine as a Sensory Recognition Element

Molecules ◽  
2020 ◽  
Vol 25 (13) ◽  
pp. 3076
Author(s):  
Saad S. M. Hassan ◽  
Ayman H. Kamel ◽  
Abd El-Galil E. Amr ◽  
Hisham S. M. Abd-Rabboh ◽  
Mohamed A. Al-Omar ◽  
...  
Keyword(s):  
Rapid Determination ◽  
Sample Pretreatment ◽  
Fast Response ◽  
Assay Method ◽  
Hydrodynamic Modes ◽  
Recognition Element ◽  
Accuracy And Precision ◽  
Nitrophenyl Octyl Ether ◽  
Wide Range ◽  
Ph Range

A simple potentiometric sensor is described for accurate, precise, and rapid determination of sulfite additives in beverages. The sensor is based on the use of cobalt phthalocyanine as a recognition material, dispersed in a plasticized poly(vinyl chloride) matrix membrane. o-Nitrophenyl octyl ether (o-NPOE) as a membrane solvent and tri-dodecylmethyl- ammonium chloride (TDMAC) as ion discriminators are used as membrane additives. Under the optimized conditions, sulfite ion is accurately and precisely measured under batch and flow injection modes of analysis. The sensor exhibits fast and linear response for 1.0 × 10−2–1.0 × 10−6 M (800–0.08 µg/mL) and 1.0 × 10−1–5.0 × 10−5 M (8000–4 µg/mL) sulfite with Nernstian slopes of −27.4 ± 0.3 and −23.7 ± 0.6 mV/concentration decade under static and hydrodynamic modes of operation, respectively. Results in good agreement with the standard iodometric method are obtained.Validation of the assay method is examined in details including precision, accuracy, bias, trueness, repeatability, reproducibility, and uncertainty and good performance characteristics of the method are obtained. The sensor response is stable over the pH range of 5 to 7 without any significant interference from most common anions. The advantages offered by the proposed sensor (i.e., wide range of assay, high accuracy and precision, low detection limit, reasonable selectivity, long term response stability, fast response, and long life span and absence of any sample pretreatment steps) suggest its use in the quality control/quality assurance routine tests in beverages industries, toxicological laboratories and by inspection authorities.

Extractive Spectrophotometric Methods for Determination of Chlorpheniramine Maleate in Pure Form, Pharmaceutical Preparations and Biological Fluids

2017 ◽  
Vol 75 ◽  
pp. 11-24
Author(s):  
Marwa El Badry Mohamed ◽  
Eman Y.Z. Frag ◽  
Hana A. El-Boraey ◽  
Safa S. El-Sanafery
Keyword(s):  
Blood Serum ◽  
Limit Of Detection ◽  
Biological Fluids ◽  
Ion Pairs ◽  
Pharmaceutical Preparations ◽  
Pure Form ◽  
Stoichiometric Ratio ◽  
Bromocresol Purple ◽  
Chlorpheniramine Maleate

In this study a simple, rapid and sensitive spectrophotometric method was developed for the determination of an antihistaminic drug chlorpheniramine maleate (CPM) in pure form, pharmaceutical preparations, spiked humane urine and spiked blood serum. This method was based on the formation of ion-pairs between the basic nitrogen of the CPM drug and four chromogenic reagents namely bromocresol purple (BCP), alizarine Red S (ARS), eriochrome cyanine R (ECR), and cresol red (CR). The extracted colored ion-pairs were measured spectrophotometrically at 390, 425, 503 and 408 nm for BCP, ARS, ECR and CR reagents, respectively. The different parameters that affect the color development between CPM drug and dyestuff reagents were extensively studied to determine the optimal conditions for the assay procedure. The reaction was studied as a function of the volume of reagents, nature of solvent, temperature, reaction time and stoichiometric ratio between the CPM drug and the reagents. Beer’s law was valid over the concentration ranges of 1-30, 1-10, 2-120 and 4-120 μg mL-1 of CPM drug using BCP, ARS, ECR and CR reagents, respectively. The Sandell sensitivity, molar absorptivity, limit of detection and limit of quantification were determined. Applications of the proposed procedure to the analysis of the pharmaceutical preparations, spiked humane urine and spiked blood serum gave reproducible and accurate results without any interference from excipients. The results obtained by the proposed method were in good agreement with those obtained by reported method. The method can be suggested for the routine analysis of the cited drug.

scholarly journals The Alternative Voltammetric Method for the Determination of Nicotine and Its Metabolite Nicotine N-Oxide

2022 ◽  
Author(s):  
Olha Dushna ◽  
Liliya Dubenska ◽  
Serhiy Plotycya ◽  
Mariana Rydchuk ◽  
Mykola Blazheyevskіy
Keyword(s):  
Limit Of Detection ◽  
Biological Fluids ◽  
Electrochemical Behaviour ◽  
Pharmaceutical Preparations ◽  
Linear Sweep Voltammetry ◽  
Differential Pulse ◽  
Analytical Form ◽  
Silver Solid Amalgam Electrode ◽  
Drugs Analysis ◽  
First Time

Abstract In the present paper, for the first time, the electrochemical behaviour of nicotine metabolite nicotine N-oxide (NNO) on static mercury dropping electrode (SMDE) and mercury meniscus modified silver solid amalgam electrode (m-AgSAE) has been reported. Nicotine N-oxide is reduced forming one peak at the potential -0.78 V on SDME and -0.86 V on m-AgSAE in Britton-Robinson buffer medium at pH 4.5 using cyclic voltammetry (CV). One electron and one proton take part in the reaction of NNO reduction. Calibration graphs for NNO determination using linear sweep voltammetry (LSV) on SDME and square-wave voltammetry (SWV) and differential pulse voltammetry (DPV) on m-AgSAE were obtained. Limit of detection (LOD) is 0.13 μM on SDME, and 0.16 μM (SWV) and 0.29 μM (DPV) on m-AgSAE. Since NNO can be used as an analytical form for nicotine voltammetric determination, so the developed methods were applied for the analysis of pharmaceutical preparations, and the recoveries from 97.3 to 104.6 % were achieved. Also, the elaborated methods were used in the analysis of biological fluids, and tobacco products. The obtained results were compared to those indicated in the certificates of drugs analysis, and to the results, obtained by reference methods (HPLC and GC).

scholarly journals Solid-Contact Ion-Selective Electrodes for Histamine Determination

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6658
Author(s):  
Siyuan Ma ◽  
You Wang ◽  
Wei Zhang ◽  
Ye Wang ◽  
Guang Li
Keyword(s):  
Biological Fluids ◽  
Gold Wire ◽  
Fast Response ◽  
Ion Selective Electrodes ◽  
Solid Contact ◽  
Long Term Stability ◽  
Artificial Cerebrospinal Fluid ◽  
Selective Membrane ◽  
Ph Range

Solid-contact ion-selective electrodes for histamine (HA) determination were fabricated and studied. Gold wire (0.5 mm diameter) was coated with poly(3,4-ethlenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT:PSS) as a solid conductive layer. The polyvinyl chloride matrix embedded with 5,10,15,20-tetraphenyl(porphyrinato)iron(iii) chloride as an ionophore, 2-nitrophenyloctyl ether as a plasticizer and potassium tetrakis(p-chlorophenyl) borate as an ion exchanger was used to cover the PEDOT:PSS layer as a selective membrane. The characteristics of the HA electrodes were also investigated. The detection limit of 8.58 × 10−6 M, the fast response time of less than 5 s, the good reproducibility, the long-term stability and the selectivity in the presence of common interferences in biological fluids were satisfactory. The electrode also performed stably in the pH range of 7–8 and the temperature range of 35–41 °C. Additionally, the recovery rate of 99.7% in artificial cerebrospinal fluid showed the potential for the electrode to be used in biological applications.

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