scholarly journals Rapid Separation and Determination of Metronidazole Benzoate and Other Antiprotozoal Drugs by Pressurized Capillary Electrochromatography

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Sulan Liao ◽  
Qilin Weng
Keyword(s):  
Capillary Electrochromatography ◽  
Phosphate Buffer Solution ◽  
Dihydrogen Phosphate ◽  
Buffer Solution ◽  
Solution Ph ◽  
Rapid Separation ◽  
Polymer Monolith ◽  
Pressurized Capillary Electrochromatography ◽  
Metronidazole Benzoate

A novel method for the rapid separation and determination of five polar 5-nitroimidazoles in water from different sources by pressurized capillary electrochromatography has been developed. Compared with the gradient elution mode and the packed nonpolar columns which were usually utilized for the separation of 5-nitroimidazoles, a simple isocratic elution mode and low-cost homemade polar molecularly imprinted polymer monolith were used in the experiment. Electrochromatographic conditions such as pH of buffer, organic modifier, concentration of buffer, and separation voltage were optimized. At 320 nm UV wavelengths, the five 5-nitroimidazoles could be baseline-separated rapidly in less than 11 min with the separation voltage of +20 kV in 10 mmol/L sodium dihydrogen phosphate-disodium hydrogen phosphate buffer solution (pH 4.82) containing 30% acetonitrile. Under the optimum conditions, the linear ranges of the metronidazole, secnidazole, tinidazole, ornidazole, and metronidazole benzoate were 0.50–100.00, 0.50–100.00, 0.80–500.00, 0.80–100.00, and 5.00–500.00 μg/mL, respectively, and the detection limits of these analytes were 0.11–0.73 μg/mL. Column efficiencies of 43 000, 36 000, 34 000, 14 000, and 29 000 plates/m were obtained for metronidazole, secnidazole, tinidazole, ornidazole, and metronidazole benzoate, respectively. The recoveries of different water samples were about 85.0–95.8%. Additionally, the proposed method has been successfully applied to the rapid separation of 5-nitroimidazoles in the locally available pure milk sample by simple pretreatment.

Non-enzymatic determination of purine nucleotides using a carbon dot modified glassy carbon electrode

2019 ◽  
Vol 11 (30) ◽  
pp. 3866-3873 ◽  
Author(s):  
R. Karthikeyan ◽  
D. James Nelson ◽  
S. Abraham John
Keyword(s):  
Glassy Carbon ◽  
Low Cost ◽  
Phosphate Buffer Solution ◽  
Purine Nucleotides ◽  
Buffer Solution ◽  
Solution Ph ◽  
Carbon Dot ◽  
Enzymatic Determination ◽  
Sensitive Determination

Selective and sensitive determination of one of the purine nucleotides, inosine (INO) using a low cost carbon dot (CD) modified glassy carbon (GC) electrode in 0.2 M phosphate buffer solution (pH 7.2) was demonstrated in this paper.

Coated Carbon Nanotubes at Nano Copper Modified GCE for Simultaneous Determination of Dopamine and Uric Acid

2012 ◽  
Vol 600 ◽  
pp. 238-241
Author(s):  
Xiao Ling Qiang ◽  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Uric Acid ◽  
Phosphate Buffer Solution ◽  
Carbon Electrode ◽  
Cu Nanoparticles ◽  
Buffer Solution ◽  
Solution Ph ◽  
Electrochemically Deposited ◽  
Coated Carbon

Copper (Cu) nanoparticles have been electrochemically deposited onto the glassy carbon electrode (GCE) surface by potentiostatic deposition method and then carbon nanotubes (CNTs) was dropped on the nano-Cu modified electrode surface to get a CNTs/nano-Cu/GCE electrode. The CNTs/nano-Cu/GCE has shown much higher electrocatalytic activity than the CNTs/GCE towards the oxidation of dopamine (DA) and uric acid (UA) in a phosphate buffer solution (pH 6.9). It can be applied to determine DA and UA with satisfactory results.

scholarly journals Electrochemical sensor for determination of hydroxylamine using functionalized Fe3O4 nanoparticles and graphene oxide modified screen-printed electrode

2021 ◽  
Author(s):  
Hamed Tashakkorian ◽  
Behnaz Aflatoonian ◽  
Peyman Mohammadzadeh Jahani ◽  
Mohammad Reza Aflatoonian
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Sensor ◽  
Fe3o4 Nanoparticles ◽  
Phosphate Buffer Solution ◽  
Electrochemical Process ◽  
Screen Printed Electrode ◽  
Buffer Solution ◽  
Solution Ph ◽  
Screen Printed

A simple strategy for determination of hydroxylamine based on Fe3O4 nanoparticles function­nalized by [2-(4-((3-(trimethoxysilyl)propylthio)methyl)1-H1,2,3-triazol-1-yl)acetic­acid] (FNPs) and graphene oxide (GO) modified screen-printed electrode (SPE), denoted as (Fe3O4 FNPs/GO/SPE), is reported. The electrochemical behavior of hydroxylamine was investigated at Fe3O4FNPs/GO/SPE by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chro­noamperometry (CHA) techniques in phosphate buffer solution (pH 7.0). Fe3O4 FNPs/GO/SPE as a novel electrochemical sensor exhibited catalytic activity toward the oxidation of hydroxyl­ami­ne. The potential of hydroxylamine oxidation was shifted to more negative potentials, and its oxidation peak current increased on the modified electrode, also indicating that under these conditions, the electrochemical process is irreversible. The electrocatalytic current of hydroxyl­amine showed a good relationship in the concentration range of 0.05–700.0 μM, with a detection limit of 10.0 nM. The proposed electrode was applied for the determination of hydroxyl­amine in water samples, too.

scholarly journals Poly (DL-valine) electro-polymerized carbon nanotube paste sensor for determination of antihistamine drug cetirizine

2020 ◽  
Author(s):  
Tigari Girish ◽  
Jamballi G. Manjunatha ◽  
Pemmatte A. Pushpanjali ◽  
Nambudumada S. Prinith ◽  
Doddarasinakere K. Ravishankar ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Organic Molecules ◽  
Phosphate Buffer Solution ◽  
Multiwalled Carbon Nanotube ◽  
Buffer Solution ◽  
Solution Ph ◽  
Multiwalled Carbon ◽  
Accumulation Time ◽  
Antihistamine Drug

Poly (DL-valine) modified multiwalled carbon nanotube paste sensor (PVLMCNTPS) was prepared by electro-polymerization route. PVLMCNTPS and bare multiwalled carbon nanotube paste sensor (BMCNTPS) morphologies and sensing properties for cetirizine (CTZ) were confirmed through a field emission scanning electron microscope (FE-SEM) and electrochemical studies, respectively. In contrast to BMCNTPS, PVLMCNTPS surface composite creates an electrocatalytic impact on the oxidation of CTZ. PVLMCNTPS properties were optimized using parameters such as accumulation time, number of polymerization cycles, solution pH, and scan rate. The optimized PVLMCNTPS was applied for the determination of cetirizine in 0.1 M phosphate buffer solution (PBS) of pH 7.0, using cyclic voltammetry (CV). It is shown that PVLMCNTPS provided analytical linearity from 2.0 to 80 µM, with a detection limit of 0.11 µM for CTZ determination. PVLMCNTPS is found highly selective for CTZ in presence of some interfering organic molecules. The stable and selective PVLMCNTPS was applied for CTZ determination in pharmaceutical pills with satisfactory results.

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 Development and Validation of an HPLC Method for Simultaneous Assay of MCI and MI in Shampoos Containing Plant Extracts

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Le Thi Huong Hoa ◽  
Vo Tran Ngoc Hung ◽  
Do Thu Trang ◽  
Thai Nguyen Hung Thu ◽  
Dinh Chi Le
Keyword(s):  
Plant Extracts ◽  
Mobile Phase ◽  
Phosphate Buffer Solution ◽  
Hplc Method ◽  
Isopropyl Myristate ◽  
Total Flow ◽  
Buffer Solution ◽  
Solution Ph ◽  
Development And Validation

A simple, easy-to-implement HPLC method was developed and validated for simultaneous determination of two isothiazolinone preservatives, methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI), in hair care shampoo containing plant extracts. In this method, shampoo samples were first dissolved in isopropyl myristate and then MCI and MI were extracted from isopropyl myristate layer by a mixture of methanol and 0.02 M phosphate buffer solution pH 3.0 (30: 70, v/v) and analyzed on an analytical biphenyl column maintained at 25°C with a mixture of methanol and water (10: 90, v/v) in isocratic elution mode as mobile phase. Total flow rate of mobile phase was maintained at 1.0 mL per minute. The UV detection was performed at 274 nm. Injection volume was 50 μl. The method was fully validated in terms of specificity, linearity, precision, accuracy, and robustness according to requirements of AOAC International and was proved as reliable and suitable for the intended application.

scholarly journals Voltammetric Approach for Pharmaceutical Samples Analysis; Simultaneous Quantitative Determination of Resorcinol and Hydroquinone

2021 ◽  
Author(s):  
Ebrahim Nabatian ◽  
Mahdi Mousavi ◽  
Mostafa Pournamdari ◽  
Saeid Ahmadzadeh
Keyword(s):  
Simultaneous Determination ◽  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Regression Equations ◽  
Carbon Paste ◽  
Buffer Solution ◽  
Solution Ph ◽  
Pharmaceutical Samples

Abstract A simple and precise analytical approach developed for single and simultaneous determination of resorcinol (RC) and hydroquinone (HQ) in pharmaceutical samples using carbon paste electrode (CPE) modified with 1-Ethyl-3-methylimidazolium tetrafluoroborate as ionic liquid and ZnFe2O4 nanoparticle. A significant enhancement in the peak current and sensitivity of the proposed sensor observed by using modifiers in the composition of working electrode compared to bare CPE which is in accordance with the results obtained from electrochemical impedance spectroscopy investigations. Electrochemical investigations revealed a well-defined irreversible oxidation peak for RC over a wide concentration range from 3.0 µM to 500 µM in 0.1 M phosphate buffer solution (pH 6.0) with the linear regression equations of Ip (µA) = 0.0276 CRC (µM) + 0.5508 (R2 = 0.997). The limit of detection and quantification for RC analysis were found to be 1.46 µM and 4.88 µM, respectively. However, the obtained SW voltammograms for simultaneous determination of RC and HQ exhibited a desirable peak separation of about 360 mV potential difference and a satisfactory linear response over the range of 50-700 µM and 5-350 µM with the favorable correlation coefficient of 0.991 and 0.995, respectively. The diffusion coefficient (D) of RC and the electron transfer coefficient (α) at the surface of ZnFe2O4/NPs/IL/CPE estimated to be 2.83×10−4 cm s−1 and 0.76. The proposed sensor as a promising and low-cost method successfully applied for determination of RC in commercial pharmaceutical formulations such as the resorcinol cream of 2% O/W emulsion available on the market with the recovery of 98.47±0.04.

The use of photogenerated iodine for the determination of isoniazid in solid dosage formulation

2021 ◽  
Vol 87 (3) ◽  
pp. 5-10
Author(s):  
E. V. Turusova ◽  
O. E. Nasakin ◽  
A. N. Lyshchikov
Keyword(s):  
Active Compound ◽  
Potato Starch ◽  
Phosphate Buffer Solution ◽  
Analytical Signal ◽  
Molar Ratio ◽  
Buffer Solution ◽  
Solution Ph ◽  
Solid Dosage ◽  
Dosage Formulation

A shot cut method for the determination of isoniazid in a solid dosage formulation (DF) has been developed. The method is based on isoniazid titration with a solution of photogenerated iodine obtained as a result of irradiation of an auxiliary solution containing potassium iodide, a mixture of sensitizers (sodium eosinate, fluorescein, auramine taken in a molar ratio of 1:1:1) and phosphate buffer solution (pH 7.5). Since the titrant content in the cell was controlled using the voltammetric method (amperometric titration with two polarized electrodes), the interaction of a physiologically active compound with the latter was accompanied by a decrease in the amount of titrant in the cell and, hence, in the current in amperometric circuit. Stabilization of the current in the circuit of the amperometric setup indicated the completeness of the reaction, and, therefore, provided estimation of the content of a physiologically active compound in the dosage formulation. Further irradiation of the solution and measurement of the generation time required to replenish the loss of titrant in the cell also made it possible to regulate the content of isoniazid in the preparation. The technique was tested on the samples of solid dosed formulations. It was shown that the components of the tablet mass (calcium stearate monohydrate, polysorbate, crospovidone and potato starch) do not affect the results of the determination of physiologically active compound provided that the analyzed form is obtained at room temperature. The determined content of isoniazid in a solid dosage formulation varies in the range of 286.0 – 296.0 mg and falls within the range recommended by the General Pharmacopoeia Monograph 1.4.2.0009.15 (285 – 315 mg), which indicates that the quality of the drug meets the GMP standards. The linear dependence of the analytical signal on the concentration of physiologically active compound is observed in the range of 161 – 1610 mg for the drug «Isoniazid. Tablets, 300 mg». The calculated detection limits and quantitative determination are 13.5 and 41.0 mg (both in terms of change in the current strength and in the time of titrant generation), respectively. The developed photochemical method for the determination of isoniazid in solid dosed formulation is easy to use, meets the requirements set out in the guidelines for validation of bioanalytical methods, and does not require expensive equipment. The method can be recommended for routine control of the DF quality indicators in any analytical laboratory.

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