scholarly journals Electroanalytical Techniques for the Detection of Selenium as a Biologically and Environmentally Significant Analyte—A Short Review

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1768
Author(s):  
Miroslav Rievaj ◽  
Eva Culková ◽  
Damiána Šandorová ◽  
Zuzana Lukáčová-Chomisteková ◽  
Renata Bellová ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Essential Element ◽  
Analytical Techniques ◽  
High Sensitivity ◽  
Stripping Voltammetry ◽  
Short Review ◽  
Electroanalytical Methods ◽  
High Concentrations ◽  
Speed Of Analysis

This short review deals with the properties and significance of the determination of selenium, which is in trace amounts an essential element for animals and humans, but toxic at high concentrations. It may cause oxidative stress in cells, which leads to the chronic disease called selenosis. Several analytical techniques have been developed for its detection, but electroanalytical methods are advantageous due to simple sample preparation, speed of analysis and high sensitivity of measurements, especially in the case of stripping voltammetry very low detection limits even in picomoles per liter can be reached. A variety of working electrodes based on mercury, carbon, silver, platinum and gold materials were applied to the analysis of selenium in various samples. Only selenium in oxidation state + IV is electroactive therefore the most of voltammetric determinations are devoted to it. However, it is possible to detect also other forms of selenium by indirect electrochemistry approach.

scholarly journals The Double Face of Ketamine—The Possibility of Its Identification in Blood and Beverages

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 813
Author(s):  
Magdalena Świądro ◽  
Paweł Stelmaszczyk ◽  
Irena Lenart ◽  
Renata Wietecha-Posłuszny
Keyword(s):  
Date Rape ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Heroin Addiction ◽  
Assisted Extraction ◽  
Low Concentrations ◽  
High Concentrations ◽  
Rosé Wine ◽  
Tof Ms

The purpose of this study was to develop and validate a high-sensitivity methodology for identifying one of the most used drugs—ketamine. Ketamine is used medicinally to treat depression, alcoholism, and heroin addiction. Moreover, ketamine is the main ingredient used in so-called “date-rape” pills (DRP). This study presents a novel methodology for the simultaneous determination of ketamine based on the Dried Blood Spot (DBS) method, in combination with capillary electrophoresis coupled with a mass spectrometer (CE-TOF-MS). Then, 6-mm circles were punched out from DBS collected on Whatman DMPK-C paper and extracted using microwave-assisted extraction (MAE). The assay was linear in the range of 25–300 ng/mL. Values of limits of detection (LOD = 6.0 ng/mL) and quantification (LOQ = 19.8 ng/mL) were determined based on the signal to noise ratio. Intra-day precision at each determined concentration level was in the range of 6.1–11.1%, and inter-day between 7.9–13.1%. The obtained precision was under 15.0% (for medium and high concentrations) and lower than 20.0% (for low concentrations), which are in accordance with acceptance criteria. Therefore, the DBS/MAE/CE-TOF-MS method was successfully checked for analysis of ketamine in matrices other than blood, i.e., rose wine and orange juice. Moreover, it is possible to identify ketamine in the presence of flunitrazepam, which is the other most popular ingredient used in DRP. Based on this information, the selectivity of the proposed methodology for identifying ketamine in the presence of other components of rape pills was checked.

Recent Electrochemical Assays on Cephalosporins

2020 ◽  
Vol 16 (4) ◽  
pp. 337-349
Author(s):  
Leyla Karadurmus ◽  
Kaan Eşme ◽  
Nurgul K. Bakirhan ◽  
Sibel A. Ozkan
Keyword(s):  
Low Cost ◽  
Linear Sweep Voltammetry ◽  
High Sensitivity ◽  
Differential Pulse ◽  
Electroanalytical Methods ◽  
Antibiotic Drugs ◽  
Short Time ◽  
Advanced Generation ◽  
Antibacterial Spectrum

: Antibiotics are an important class among drugs because they are a significant agent to deal with infections. Cephalosporins are a very important group of antibiotics in the β-lactam class. The cephalosporins are semisynthetic antibiotics derived from products of the fungus Cephalosporium. Cephalosporins are classified as first, second, third, fourth, and advanced generation, based largely on their antibacterial spectrum and stability to β-lactamases. Electrochemical methods have been used for the determination of cephalosporin just as used in the determination of many antibiotic drugs. Electroanalytical methods present generally high sensitivity, low cost, low requirements, ease of preparation of the samples in a very short time, and a short analysis time. The most commonly used types are cyclic voltammetry, differential pulse voltammetry, square wave voltammetry and linear sweep voltammetry. The aim of this review is to evaluate the advantages and uses of electroanalytical methods used in the determination of cephalosporins. In addition, current applications of the methods to the pharmaceutical analysis of cephalosporins will also be summarized in a table.

Electrochemical Detection of Amaranth in Food Based on the Expanded Graphite Paste Electrode

2013 ◽  
Vol 96 (3) ◽  
pp. 625-629 ◽  
Author(s):  
Mei L Wang ◽  
Jing Zhang ◽  
Ni N Ding ◽  
Xiao L Zhu ◽  
Zhi D Chen
Keyword(s):  
Expanded Graphite ◽  
High Sensitivity ◽  
Stripping Voltammetry ◽  
Pulse Amplitude ◽  
Food Samples ◽  
Experimental Conditions ◽  
Accumulation Time ◽  
Graphite Paste Electrode ◽  
Paste Electrode

Abstract A sensitive and simple electrochemical method was developed for successful determination of amaranth in food samples by square-wave adsorptive stripping voltammetry based on an expanded graphite paste electrode (EGPE). The EGPE has strong and sensitive voltammetric responses to amaranth, owing to the multiporous structure and large surface area of EG. The electroanalytical determination of this azo dye was found to be optimal in Britton-Robinson buffer solutions (pH 7.0) under the following experimental conditions: accumulation time, 400 s; accumulation potential, 0.4 V; pulse amplitude, 25 mV; and frequency, 10 Hz. Under the optimum experimental conditions, the oxidation peak current was proportional to the concentration of amaranth over two ranges from 0.01 to 0.1 and 0.1 to 4.0 μM. These linear ranges of the EGPE toward amaranth were wider than other electrodes reported before. The LOD was estimated to be 0.005 μM (S/N = 3:1). The developed method was applied to the determination of amaranth in retsina samples, and the results were confirmed by HPLC. Statistical analysis of these data showed that the results of the two methods compared favorably. This work provides a simple and easy approach to the determination of amaranth in foods with high sensitivity and excellent selectivity.

scholarly journals A study of the antioxidative behavior of phenolic acids, in aqueous herb extracts, using a dsDNA biosensor

2012 ◽  
Vol 10 (4) ◽  
pp. 1280-1289 ◽  
Author(s):  
Elina Skeva ◽  
Stella Girousi
Keyword(s):  
Phenolic Acids ◽  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Deposition Potential ◽  
Dna Biosensors ◽  
High Concentrations ◽  
Vitro Analysis ◽  
Herb Extracts

AbstractElectrochemical DNA biosensors are promising tools for the fast, inexpensive and simple in vitro analysis for the determination of free radicals and antioxidants. High concentrations of antioxidants in such compounds as phenolic acids and plant extracts, act as free radical terminators which reduce the effect of the oxidative dam-age on DNA. The electrochemical behavior of three representative phenolic acids, caffeic acid, gallic acid and trolox were studied by cyclic voltammetry. Moreover, the determination of the above antioxidants under the optimized conditions (scan rate, deposition potential and time) using differential pulse voltammetry was also investigated. In vitro studies focused on their antioxidative effect were performed by adsorptive transfer stripping voltammetry and dsDNA biosensor. Using Fenton’s system, with FeSO4 and H2O2 was chosen as a strong oxidative system. This biosensor was applied as a screening antioxidant test in order to estimate the antioxidant capacity of aqueous herb extracts.

Selenium-induced oxidative stress in coffee cell suspension cultures

2007 ◽  
Vol 34 (5) ◽  
pp. 449 ◽  
Author(s):  
Rui A. Gomes-Junior ◽  
Priscila L. Gratão ◽  
Salete A. Gaziola ◽  
Paulo Mazzafera ◽  
Peter J. Lea ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Suspension ◽  
Sodium Selenite ◽  
Essential Element ◽  
Cell Suspension Cultures ◽  
Suspension Cultures ◽  
Severe Reduction ◽  
Opposite Behavior ◽  
High Concentrations ◽  
Antioxidant Reactions

Selenium (Se) is an essential element for humans and animals that is required for key antioxidant reactions, but can be toxic at high concentrations. We have investigated the effect of Se in the form of selenite on coffee cell suspension cultures over a 12-day period. The antioxidant defence systems were induced in coffee cells grown in the presence of 0.05 and 0.5 mm sodium selenite (Na2SeO3). Lipid peroxidation and alterations in antioxidant enzymes were the main responses observed, including a severe reduction in ascorbate peroxidase activity, even at 0.05 mm sodium selenite. Ten superoxide dismutase (SOD) isoenzymes were detected and the two major Mn-SOD isoenzymes (bands V and VI) responded more to 0.05 mm selenite. SOD band V exhibited a general decrease in activity after 12 h of treatment with 0.05 mm selenite, whereas band VI exhibited the opposite behavior and increased in activity. An extra isoenzyme of glutathione reductase (GR) was induced in the presence of selenite, which confirmed our previous results obtained with Cd and Ni indicating that this GR isoenzyme may have the potential to be a marker for oxidative stress in coffee.

Use of an Adjustable Impact Bead in the Analysis of Solutions in Organic Solvents by Flame Atomic Absorption

1992 ◽  
Vol 46 (8) ◽  
pp. 1231-1234 ◽  
Author(s):  
John B. Willis ◽  
Barry T. Sturman
Keyword(s):  
Atomic Absorption ◽  
Organic Solvents ◽  
Simple Technique ◽  
Flame Atomic Absorption ◽  
High Boiling Point ◽  
High Concentrations ◽  
The Impact ◽  
Speed Of Analysis ◽  
Solution Uptake

Throughput of organic solvent aerosol to the flame of an atomic absorption spectrometer may be controlled by varying the position of the impact bead relative to the nebulizer, instead of varying the solution uptake rate of the nebulizer. The usefulness of this simple technique has been demonstrated for a range of elements in three organic solvents (4-methylpentan-2-one, xylene, and a high-boiling-point iso-paraffin solvent), with air/C2H2 and N2O/C2H2 flames. It is shown that the adjustment of the impact bead alone allows the determination of high concentrations of copper and iron in lubricating oils without undue dilution of the sample and can result in significant improvements in the speed of analysis.

A Novel Sensor of Poly(Vinyl Alcohol) Incorporated Multi-Walled Carbon Nanotubes for Voltammetric Determination of Cu (II)

2012 ◽  
Vol 600 ◽  
pp. 124-127
Author(s):  
De Ling Chi ◽  
Kai Zhao ◽  
Fei Fei Zhang ◽  
Zong Hua Wang
Keyword(s):  
Carbon Nanotubes ◽  
Vinyl Alcohol ◽  
Anodic Stripping Voltammetry ◽  
High Sensitivity ◽  
Stripping Voltammetry ◽  
Poly Vinyl Alcohol ◽  
Accumulation Time ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

An electrochemical sensor for the detection of Cu (II) ion is described by using poly (vinyl alcohol) (PVA) and carboxylic multi-walled carbon nanotubes (c-MWNT) modified glassy carbon electrode (GCE) by anodic stripping voltammetry (ASV). PVA/c-MWNT film greatly improves the sensitivity of determining Cu (II). The striping peak currents change linearly with the concentration of Cu (II) from 1.0×10-8to 8.0×10-5mol/L for an accumulation time of 200 s, correlation coefficient r = 0.9980. The detection limit is as low as 5.0×10-9mol/L. The high sensitivity, selectivity, and stability of the PVA/c-MWNT film demonstrated its practical application.

scholarly journals Determination of Folic Acid Using Biosensors—A Short Review of Recent Progress

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3360
Author(s):  
Alessio Di Tinno ◽  
Rocco Cancelliere ◽  
Laura Micheli
Keyword(s):  
Folic Acid ◽  
Biological Fluid ◽  
Low Cost ◽  
Analytical Techniques ◽  
Short Review ◽  
Electrochemical Determination ◽  
Water Soluble ◽  
Methylation Of Dna ◽  
Vitamin B9

Folic acid (FA) is the synthetic surrogate of the essential B vitamin folate, alternatively named folacin, pteroylglutamic acid or vitamin B9. FA is an electroactive compound that helps our body to create and keep our cells healthy: it acts as the main character in a variety of synthetic biological reactions such as the synthesis of purines, pyrimidine (thus being indirectly implied in DNA synthesis), fixing and methylation of DNA. Therefore, physiological folate deficiency may be responsible for severe degenerative conditions, including neural tube defects in developing embryos and megaloblastic anaemia at any age. Moreover, being a water-soluble molecule, it is constantly lost and has to be reintegrated daily; for this reason, FA supplements and food fortification are, nowadays, extremely diffused and well-established practices. Consequently, accurate, reliable and precise analytical techniques are needed to exactly determine FA concentration in various media. Thus, the aim of this review is to report on research papers of the past 5 years (2016–2020) dealing with rapid and low-cost electrochemical determination of FA in food or biological fluid samples.

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