Electrochemical Analysis of Solids. A Review

2002 ◽  
Vol 67 (2) ◽  
pp. 163-208 ◽  
Author(s):  
Tomáš Grygar ◽  
Frank Marken ◽  
Uwe Schröder ◽  
Fritz Scholz
Keyword(s):  
Mass Measurement ◽  
Analytical Techniques ◽  
Electrochemical Analysis ◽  
Composite Electrodes ◽  
Carbon Paste ◽  
Voltammetric Analysis ◽  
Organic Solids ◽  
Force Microscopy ◽  
Sensitivity Specificity ◽  
Constituent Elements

The topic of the review is the electrochemical analysis of solids aimed to identify or determine their phase or elemental composition, analyse the composition of solid mixtures, characterise their electrochemistry-related properties and analyse the redox state of the constituent elements. The ways of the electrode preparation are discussed with a special attention paid to compact and composite electrodes including carbon-paste electrodes, and direct immobilisation of powders on a working electrode. Examples are given of simultaneous electrochemical measurements combined with X-ray diffraction, optical or atomic force microscopy, and mass measurement by quartz microbalance. The state-of-art of voltammetric analysis of inorganic and organic solids achieved in the last two decades is systematically reviewed with the aim to find cases, when electrochemistry can compete successfully with other analytical techniques as for sensitivity, specificity, and sample consumption. Electrochemical methods are shown to be a perspective tool for redox analysis of catalysts, combined elemental and phase analysis of inorganic pigments and minerals, characterisation of solid solutions, metalloorganic and organic solids. A review with 196 references.

scholarly journals Recent Advances in the Electrochemical Sensing of Venlafaxine: An Antidepressant Drug and Environmental Contaminant

Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3675
Author(s):  
Somayeh Tajik ◽  
Hadi Beitollahi ◽  
Zahra Dourandish ◽  
Kaiqiang Zhang ◽  
Quyet Van Le ◽  
...  
Keyword(s):  
Antidepressant Drug ◽  
Analytical Techniques ◽  
High Sensitivity ◽  
Electrochemical Determination ◽  
Electrochemical Sensing ◽  
Carbon Paste ◽  
Low Concentrations ◽  
Adverse Influence ◽  
Living Organisms ◽  
Sensitivity Specificity

Venlafaxine (VEN), as one of the popular anti-depressants, is widely utilized for the treatment of major depressive disorder, panic disorder, as well as anxiety. This drug influences the chemicals in the brain, which may result in imbalance in depressed individuals. However, venlafaxine and its metabolites are contaminants in water. They have exerted an adverse influence on living organisms through their migration and transformation in various forms of adsorption, photolysis, hydrolysis, and biodegradation followed by the formation of various active compounds in the environment. Hence, it is crucial to determine VEN with low concentrations in high sensitivity, specificity, and reproducibility. Some analytical techniques have been practically designed to quantify VEN. However, electroanalytical procedures have been of interest due to the superior advantages in comparison to conventional techniques, because such methods feature rapidity, simplicity, sensitivity, and affordability. Therefore, this mini-review aims to present the electrochemical determination of VEN with diverse electrodes, such as carbon paste electrodes, glassy carbon electrodes, mercury-based electrodes, screen-printed electrodes, pencil graphite electrodes, and ion-selective electrodes.

Indicator carbon-paste electrode for voltammetric analysis

2020 ◽  
Vol 86 (2) ◽  
pp. 5-14
Author(s):  
D. M. Aronbaev ◽  
S. D. Aronbaev ◽  
G. Z. Narmaeva ◽  
D. T. Isakova
Keyword(s):  
Carbon Paste Electrode ◽  
Carbon Paste ◽  
Voltammetric Analysis ◽  
Paste Electrode

scholarly journals Extracellular Vesicles Analysis in the COVID-19 Era: Insights on Serum Inactivation Protocols towards Downstream Isolation and Analysis

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 544
Author(s):  
Roberto Frigerio ◽  
Angelo Musicò ◽  
Marco Brucale ◽  
Andrea Ridolfi ◽  
Silvia Galbiati ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Analytical Techniques ◽  
Heat Inactivation ◽  
Force Microscopy ◽  
Atomic Force ◽  
Droplet Pcr ◽  
Detergent Treatment ◽  
Routine Procedures ◽  
The Impact ◽  
Mirna Content

Since the outbreak of the COVID-19 crisis, the handling of biological samples from confirmed or suspected SARS-CoV-2-positive individuals demanded the use of inactivation protocols to ensure laboratory operators’ safety. While not standardized, these practices can be roughly divided into two categories, namely heat inactivation and solvent-detergent treatments. These routine procedures should also apply to samples intended for Extracellular Vesicles (EVs) analysis. Assessing the impact of virus-inactivating pre-treatments is therefore of pivotal importance, given the well-known variability introduced by different pre-analytical steps on downstream EVs isolation and analysis. Arguably, shared guidelines on inactivation protocols tailored to best address EVs-specific requirements will be needed among the analytical community, yet deep investigations in this direction have not yet been reported. We here provide insights into SARS-CoV-2 inactivation practices to be adopted prior to serum EVs analysis by comparing solvent/detergent treatment vs. heat inactivation. Our analysis entails the evaluation of EVs recovery and purity along with biochemical, biophysical and biomolecular profiling by means of a set of complementary analytical techniques: Nanoparticle Tracking Analysis, Western Blotting, Atomic Force Microscopy, miRNA content (digital droplet PCR) and tetraspanin assessment by microarrays. Our data suggest an increase in ultracentrifugation (UC) recovery following heat treatment; however, it is accompanied by a marked enrichment in EVs-associated contaminants. On the other hand, solvent/detergent treatment is promising for small EVs (<150 nm range), yet a depletion of larger vesicular entities was detected. This work represents a first step towards the identification of optimal serum inactivation protocols targeted to EVs analysis.

scholarly journals THE USE OF COPPER INDICATOR ELECTRODES IN VOLTAMMETRIC ANALYSIS

2016 ◽  
Vol 11 (5) ◽  
pp. 26-41 ◽  
Author(s):  
L. Yu. Martynov ◽  
O. A. Naumova ◽  
N. K. Zaytsev ◽  
I. Yu. Lovchinovsky
Keyword(s):  
Electrochemical Sensors ◽  
Chemical Properties ◽  
Electrochemical Analysis ◽  
Voltammetric Analysis ◽  
Advantages And Disadvantages ◽  
Copper Electrodes ◽  
Inorganic Substances ◽  
Physico Chemical ◽  
Recent Trends ◽  
Solid Electrodes

The review describes the application of solid electrodes based on copper for voltammetric analysis of major classes of organic and inorganic substances over the last fifty years. Despite the fact that there are many reviews of individual solid electrodes this review offers the first comprehensive report on all forms of copper electrodes. The advantages and disadvantages of copper electrodes in comparison with electrodes made of other metals are discussed. Varieties of copper electrodes, their basic physico-chemical properties and some specific characteristics of their surface are described. The electrochemical behavior of copper in aqueous solutions and electrocatalytic mechanisms of transformations of matter on its surface are reported. Examples of the use of electrochemical copper sensors for flow-injection analysis and liquid chromatography are given. Recent trends of the use of copper micro- and nanostructured electrodes in electrochemical analysis are reviewed. The prospects of using copper as a material for the creation of new electrochemical sensors are shown.

scholarly journals Synthesis of Metarhizium anisopliae–Chitosan Nanoparticles and Their Pathogenicity against Plutella xylostella (Linnaeus)

2021 ◽  
Vol 10 (1) ◽  
pp. 1
Author(s):  
Jianhui Wu ◽  
Cailian Du ◽  
Jieming Zhang ◽  
Bo Yang ◽  
Andrew G. S. Cuthbertson ◽  
...  
Keyword(s):  
Plutella Xylostella ◽  
Metarhizium Anisopliae ◽  
Chitosan Nanoparticles ◽  
Analytical Techniques ◽  
X Ray ◽  
Synthesis Of Nanoparticles ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Analysis

Nanotechnology is increasingly being used in areas of pesticide production and pest management. This study reports the isolation and virulence of a new Metarhizium anisopliae isolate SM036, along with the synthesis and characterization of M. anisopliae–chitosan nanoparticles followed by studies on the efficacy of nanoparticles against Plutella xylostella. The newly identified strain proved pathogenic to P. xylostella under laboratory conditions. The characterization of M. anisopliae–chitosan nanoparticles through different analytical techniques showed the successful synthesis of nanoparticles. SEM and HRTEM images confirmed the synthesis of spherical-shaped nanoparticles; X-ray diffractogram showed strong peaks between 2θ values of 16–30°; and atomic force microscopy (AFM) analysis revealed a particle size of 75.83 nm for M. anisopliae–chitosan nanoparticles, respectively. The bioassay studies demonstrated that different concentrations of M. anisopliae–chitosan nanoparticles were highly effective against second instar P. xylostella under laboratory and semi-field conditions. These findings suggest that M. anisopliae–chitosan nanoparticles can potentially be used in biorational P. xylostella management programs.

scholarly journals Natural and Activated Allophane Catalytic Activity Based on the Microactivity Test in Astm Norm 3907/D3907M-2019

2020 ◽  
Vol 10 (9) ◽  
pp. 3035
Author(s):  
Edward Henry Jiménez Calderón ◽  
Ana Emperatriz Paucar Tipantuña ◽  
Paulina Fernanda Herrera Mullo ◽  
Daniel Alejandro Hidalgo Cháfuel ◽  
Washington Ruiz ◽  
...  
Keyword(s):  
Analytical Techniques ◽  
Bet Surface Area ◽  
Navier Stokes ◽  
Maximum Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Catalytic Activation ◽  
Atomic Force ◽  
Activating Agent

The optimal conditions of the catalytic activation of allophane were evaluated for possible use as a catalyst within a fluidized bed catalytic cracking unit (FCC). The physicochemical properties of natural allophane and activated allophane were studied by using an alkaline activating agent, followed by a hydrothermal treatment. For the characterization, analytical techniques were used: Fourier transform infrared spectroscopy, particle size, (BET) surface area, thermogravimetry (TGA), X-ray diffraction (XRD), chemisorption, X-ray fluorescence (XRF), atomic force microscopy (AFM), and chromatography. The catalytic evaluation was determined by the (MAT) micro activity test equipment constructed according to ASTM D-3907/D3907M-2019. In addition, the Navier–Stokes 3D equations (nonlinear partial derivatives) were studied, which allow studying molecular dynamics contributing substantively to chemical kinetics describing the process of decomposition of crude oil in thermal cracking, determining the maximum temperature at which it retains its properties through the action of heat.

scholarly journals Moxifloxacin Hydrochloride Electrochemical Detection at Gold Nanoparticles Modified Screen-Printed Electrode

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2797 ◽  
Author(s):  
M. Shehata ◽  
Amany M. Fekry ◽  
Alain Walcarius
Keyword(s):  
Gold Nanoparticles ◽  
Chemical Characterization ◽  
Differential Pulse ◽  
Carbon Composite ◽  
Rapid Screening ◽  
Composite Electrodes ◽  
Carbon Paste ◽  
Screen Printed Electrode ◽  
Physico Chemical ◽  
Screen Printed

It appeared that either the carbon paste or the screen-printed carbon electrodes that were modified with gold nanoparticles (AuNPs) gave rise to the largest current responses after a rapid screening of various nanomaterials as modifiers of carbon composite electrodes in view of designing an electrochemical sensor for Moxifloxacin Hydrochloride (Moxi). The screen-printed electrode (SPE) support was preferred over the carbon paste one for its ability to be used as disposable single-use sensor enabling the circumvention of the problems of surface fouling encountered in the determination of Moxi. The response of AuNPs modified SPE to Moxi was investigated by cyclic voltammetry (CV) (including the effect of the potential scan rate and the pH of the medium), chronoamperometry, and differential pulse voltammetry (DPV) after morphological and physico-chemical characterization. DPV was finally applied to Moxi detection in phosphate buffer at pH 7, giving rise to an accessible concentration window ranging between 8 µM and 0.48 mM, and the detection and quantification limits were established to be 11.6 µM and 38.6 µM, correspondingly. In order to estimate the applicability of Moxi identification scheme in actual trials, it was practiced in a human baby urine sample with excellent recoveries between 99.8 % and 101.6 % and RSDs of 1.1–3.4%, without noticeable interference.

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