Electrochemical Determination of Heparin in Pharmaceuticals with Using Malachite Green

2014 ◽  
Vol 1040 ◽  
pp. 292-296 ◽  
Author(s):  
Darya A. Vishenkova ◽  
E.I. Korotkova ◽  
Elena V. Dorozhko
Keyword(s):  
Malachite Green ◽  
Electrochemical Determination ◽  
Constant Current ◽  
Potential Range ◽  
Reduction Peak ◽  
Optimum Conditions ◽  
Buffer Solution ◽  
Cathodic Potential ◽  
Current Sweep

In this paper for determination of heparin in pharmaceuticals by constant-current sweep voltammetry on the mercury-film electrode (MFE) we used cationic malachite green (MG) dye which is capable to form a complex with heparin. In the 0.05 M potassium tetraoxalate (KH3C4O8∙ 2H2O) buffer solution with pH 1.65 MG had a well-defined peak of electroreduction at -0.46 V (vs. CSE). During the study of electrochemical properties of heparin in complex with MG in cathodic potential range from 0.0 V to -1.3 V on MFE besides the signal from the dye at E = - 0.46 V the second signal at E = –0.87 V was found. Increasing the concentration of heparin in the solution led to decrease of signal intensity at E = -0.87 V. Optimum conditions for the electrochemical determination of heparin in dosage form with using MG were picked up. Influence of auxiliary components of heparin pharmacological solution on electroreduction of the complex MG-Hep was investigated. Under optimal conditions the decrease of reduction peak currents at E = -0.87 V was proportional to heparin concentration in the range from 3.9 ∙ 10-4mg/ml to 3.9 ∙ 10-3mg/ml.

A simple linear sweep voltammetric method for the determination of double-stranded DNA with malachite green

2006 ◽  
Vol 60 (3) ◽  
Author(s):  
W. Sun ◽  
J. You ◽  
X. Hu ◽  
K. Jiao
Keyword(s):  
Malachite Green ◽  
Interaction Mechanism ◽  
High Sensitivity ◽  
Electrochemical Determination ◽  
Supramolecular Complex ◽  
Linear Sweep ◽  
Buffer Solution ◽  
Peak Current ◽  
Double Stranded Dna

AbstractIn pH 3.5 Britton—Robinson buffer solution double-stranded (ds) DNA can react with malachite green (MG) to form an interaction complex, which resulted in the decrease of the electrochemical response of MG, MG had a well-defined second-order derivative linear sweep voltammetric peak at −0.73 V (vs. SCE). After the addition of dsDNA into MG solution, the reductive peak current decreased with the positive shift of peak potential, which was the typical characteristic of intercalation. Based on the interaction, an indirect electrochemical determination method for dsDNA was established. The optimum conditions for the reaction were investigated and there were little or no interferences from the commonly coexisting substances. The decrease of peak current was linear with the concentration of dsDNA over the range of 0.8–12.0 µg cm−3 with the linear regression equation as ΔI p″/nA = 91.70 C/(µg cm−3) + 74.55 (n = 10, γ = 0.990). The detection limit was calculated as 0.46 µg cm−3 (3σ). The method had high sensitivity and was further applied to the dsDNA synthetic samples with satisfactory result. The interaction mechanism was discussed with the intercalation of DNA-MG to form a supramolecular complex and the stoichiometry of the supramolecular complex was calculated by electrochemical method with the binding number 3 and the binding constant 2.35 × 1015 (mol dm−3)−3.

scholarly journals Linear sweep polarographic determination of nucleic acids using acridine orange as a bioprobe

2007 ◽  
Vol 72 (11) ◽  
pp. 1085-1094 ◽  
Author(s):  
Wei Sun ◽  
Na Zhao ◽  
Xianlong Yuan ◽  
Kui Jiao
Keyword(s):  
Aqueous Solution ◽  
Acridine Orange ◽  
Electrochemical Method ◽  
Electrochemical Determination ◽  
Determination Method ◽  
Linear Regression Equation ◽  
Peak Potential ◽  
Linear Sweep ◽  
Buffer Solution

The interaction of acridine orange (AO) with double-stranded (ds) DNA in aqueous solution was investigated by linear sweep polarography (LSP) on a dropping mercury working electrode (DME). In pH 2.5 Britton-Robinson (B-R) buffer solution, AO had a sensitive linear sweep polarographic reductive peak at -0.89 V (vs. SCE), which could be greatly inhibited by the addition of dsDNA, with a positive shift of the peak potential. Based on the decrease of the reductive peak current, a new quantitative electrochemical determination method for dsDNA was developed with a linear range of 2.0?20.0 mg l-1 and the linear regression equation: ?Ip" (nA) = 111.90 C (mg l-1)+125.32 (n = 9, ? = 0.997). The influences of commonly co-existing substances, such as metal ions, amino acid, etc., on the determination were also investigated. The method is sensitive, rapid and simple with good selectivity. The new proposed method was further applied to the detection of RNA and three synthetic samples containing dsDNA with satisfactory results. The binding number and the equilibrium constant between dsDNA and AO were calculated by an electrochemical method.

Rapid Electroanalytical Method for Determination of Nebivolol at a Boron-Doped Diamond Electrode

2015 ◽  
Vol 98 (6) ◽  
pp. 1535-1541 ◽  
Author(s):  
Biljana Nigović ◽  
Ana Mornar ◽  
Mario Završki
Keyword(s):  
High Speed ◽  
Comparative Method ◽  
Potential Range ◽  
Boron Doped Diamond ◽  
Buffer Solution ◽  
Diamond Electrode ◽  
Boron Doped ◽  
Boron Doped Diamond Electrode ◽  
Electroanalytical Method

Abstract A boron-doped diamond electrode provided a sensitive and cost-effective sensing platform for detection and quantitative determination of novel beta(1)-adrenergic receptor antagonist nebivolol. The net square-wave voltammetric response at 1.31 V related to the oxidation of nebivolol was obtained in Britton-Robinson buffer solution at pH 8. It increased linearly with the drug concentration in the range of 2.5 × 10–7 to 1.5 × 10–5 M. The LOD attained was 3.2 × 10–8 M. The practical analytical approach was illustrated by high speed quantification of nebivolol in a commercial pharmaceutical formulation. The RP-HPLC was selected as a comparative method for evaluating the proposed electroanalytical method. The newly developed method at the unmodified electrode surface was faster and simpler in comparison with HPLC (the retention time was 17.6 min), and only 6 s was necessary for direct voltammetric measurement in the potential range from 0.5 to 1.7 V with a 2 mV potential step and pulse frequency of 100 Hz.

scholarly journals A novel dopamine electrochemical sensor based on La3+/ZnO nanoflower modified graphite screen printed electrode

2019 ◽  
Vol 9 (3) ◽  
pp. 187-195 ◽  
Author(s):  
Somayeh Tajik ◽  
Hadi Beitollahi ◽  
Mohammad Reza Aflatoonian
Keyword(s):  
Modified Electrode ◽  
Phosphate Buffer Solution ◽  
High Sensitivity ◽  
Differential Pulse ◽  
Electrochemical Determination ◽  
Screen Printed Electrode ◽  
Buffer Solution ◽  
Optimized Conditions ◽  
Screen Printed

Flower-like La3+/ZnO nanocomposite was facile synthesized. A simple and ultrasensitive sensor based on graphite screen printed electrode (SPE) modified by La3+/ZnO nanoflower was developed for the electrochemical determination of dopamine. The electrochemical behavior of dopamine was studied in 0.1 M phosphate buffer solution (PBS) using cyclic voltammetry (CV), chronoamperometry (CA) and differential pulse voltammetry (DPV). Compared with the unmodified graphite screen printed electrode, the modified electrode facilitates the electron transfer of dopamine, since it notably increases the oxidation peak current of dopamine. Also, according to CV results the maximum oxidation of dopamine on La3+/ZnO/SPE occurs at 150 mV which is about 140 mV more negative compared with unmodified SPE. Under optimized conditions, the modified electrode exhibited a linear response over the concentration range from 0.15 to 300.0 μM, with a detection limit of 0.08 μM (S/N = 3). The proposed sensor exhibited a high sensitivity, good stability and was successfully applied for dopamine determination in dopamine ampoule, with high recovery.

Electrochemical Determination of Catechin, Protocatechuic Acid, and L-Lactic Acid Based on Voltammetric Response of Ferroceneboronic Acid

2014 ◽  
Vol 97 (6) ◽  
pp. 1742-1745 ◽  
Author(s):  
Wenxiu Shi ◽  
Junxia Wang ◽  
Lei Zhu ◽  
Meizhi Cai ◽  
Xiaoyan Du
Keyword(s):  
Abdominal Pain ◽  
Lactic Acid ◽  
Protocatechuic Acid ◽  
Differential Pulse ◽  
Electrochemical Determination ◽  
Electrochemical Technique ◽  
Reduction Peak ◽  
Cyclic Voltammogram ◽  
Carbon Electrode

Abstract An electrochemical technique for the determination of catechin, protocatechuic acid, and L-lactic acid has been developed using ferroceneboronic acid (FBA) as an electrochemical probe. The principle is based on the changes in voltammograms of FBA associated with selective binding of the analytes to FBA. A cyclic voltammogram and a differential pulse voltammogram (DPV) of FBA were recorded on a glassy carbon electrode in the presence of the analytes. The oxidation or reduction peak currents of FBA were decreased in the presence of the analytes, depending on their concentrations. The DPV measurements provided useful calibration graphs in the concentration range of 0.5–4.0 × 10–3 M catechin, 0.1–1.2 × 10–5 M protocatechuic acid, and 0.5–40 × 10–5 M L-lactic acid. The proposed method was successfully applied to the analysis of catechin in abdominal pain water medicine.

Spectrofluorimetric Determination of Bilirubin Using Enoxacine-Terbium Probe

2014 ◽  
Vol 556-562 ◽  
pp. 421-424 ◽  
Author(s):  
Wei Wei Bian
Keyword(s):  
Detection Limit ◽  
Fluorescence Intensity ◽  
Trace Amount ◽  
Optimum Conditions ◽  
Serum Samples ◽  
Buffer Solution ◽  
Spectrofluorimetric Method ◽  
Spectrofluorimetric Determination ◽  
Terbium Ion

A new spectrofluorimetric method was developed for determination of trace amount of bilirubin. Using enoxacine–terbium ion as a fluorescent probe, in the buffer solution of pH=5.8, BR can remarkably reduce the fluorescence intensity of the ENX-Tb3+ complex at λ=545nm and the reduced fluorescence intensity of Tb3+ ion is in proportion to the concentration of BR. Optimum conditions for the determination of BR were also investigated. The linear range and detection limit for the determination of BR are 1.0×10-7～4.5×10-6mol/L and 8.1×10-8mol/L. This method is simple, practical and can be successfully applied to assess BR in serum samples.

Metal-free graphene-based nanoelectrodes for the electrochemical determination of ascorbic acid (AA) and p-nitrophenol (p-NP): implication towards biosensing and environmental monitoring

2021 ◽  
Vol 45 (10) ◽  
pp. 4666-4674
Author(s):  
Vijay S. Sapner ◽  
Bhaskar R. Sathe
Keyword(s):  
Ascorbic Acid ◽  
Phosphate Buffer Solution ◽  
Electrochemical Determination ◽  
Buffer Solution ◽  
Functionalized Graphene Oxide ◽  
Free Graphene ◽  
Potential Stability ◽  
Current Potential

Herein, tyramine functionalized graphene oxide electrocatalyst is used for the electrochemical determination of ascorbic acid and p-nitrophenol in 1 M phosphate buffer solution at pH-7  with long term current/potential stability and reproducibility.

The Spectrophotometric Determination of Co(II) in Microbe Media

2013 ◽  
Vol 838-841 ◽  
pp. 2034-2039
Author(s):  
E Zhang ◽  
Xiao Ming Chen ◽  
Mei Liu ◽  
Xiao Ling Liu ◽  
Yan Xu ◽  
...  
Keyword(s):  
Spectrophotometric Determination ◽  
Bacterial Culture ◽  
Ph Value ◽  
Culture Media ◽  
Calibration Graph ◽  
Optimum Conditions ◽  
Buffer Solution ◽  
Standard Order ◽  
Solution Volume

The spectrophotometric determination has been widely used by virtue of low investment, simple equipment, convenient operation and high accuracy. The study discussed the application of picramazochrom spectrophotometry to measure Co (II) in the bacterial culture media including LB, NA and TGY medium. The parameters of chromogenic reaction containing absorption wavelength, buffer solution volume, chromogenic reagent volume and developing time were optimized. Under optimum conditions, the calibration graph was linear in the concentration range of 0~1.5mg/L (r2=0.9991) for Co (II). The LB, NA and TGY medium prepared with standard order (pH 7.0~7.4) have obvious influences on the measurement of Co (II) under shaking conditions (37°C, 120rpm), and the influence rates up to 43.46%, 40.32% and 18.03%, respectively. After the pH value of these media being adjusted to between 5 and 6, the influence rates were interestingly controlled in 5%. This picramazochrom spectrophotometry can be successfully applied to determine the Co (II) concentration in microbe media.

Electrochemical Determination of Norepinephrine at Poly (p-aminobenzenesulfonic Acid) Modified Sensor

2020 ◽  
Vol 16 (5) ◽  
pp. 591-600
Author(s):  
Şevket Zişan Yağcı ◽  
Ebru Kuyumcu Savan ◽  
Gamze Erdoğdu
Keyword(s):  
Ascorbic Acid ◽  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Differential Pulse ◽  
Electrochemical Determination ◽  
Buffer Solution ◽  
Oxidation Current ◽  
Pulse Voltammetry ◽  
Modified Sensor

Objective: In this study, it was aimed to prepare an electrochemical sensor capable of assigning Norepinephrine in the presence of an interference such as ascorbic acid. Methods: A sensitive modified sensor was prepared by electrodeposition of p-aminobenzenesulfonic acid (p-ABSA) to the glassy carbon electrode by cyclic voltammetry. The electrooxidation of Norepinephrine was accomplished by cyclic and differential pulse voltammetry. Results: The current values were enhanced and the peak potentials of Norepinephrine and ascorbic acid were separated at the sensor compared to the bare electrode. There was linearity between the oxidation current and concentration of Norepinephrine ranging from 0.5 to 99.8 μM in phosphate buffer solution at pH 7.0. The limit of detection was 10.0 nM and the sensitivity was 0.455 μA/μM. Conclusion: The determination of Norepinephrine was successfully performed in real samples such as blood serum and urine at the poly (p-ABSA) sensor. To the best of our knowledge, this is the first study to detect Norepinephrine in the presence of ascorbic acid at poly (p-ABSA) modified sensor in the literature.

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