Determination of Lead Traces by Stripping Voltammetry Using Ti(N,C) Working Electrodes

2010 ◽  
Vol 65 ◽  
pp. 168-173
Author(s):  
Marta Ziemnicka ◽  
Bogusław Baś ◽  
Mateusz Jeż ◽  
Ludosław Stobierski
Keyword(s):  
Electron Microscopy ◽  
Electrode Surface ◽  
Stripping Voltammetry ◽  
Electrochemical Activation ◽  
Trace Metal Analysis ◽  
Response Performance ◽  
Disc Electrodes ◽  
First Time

Electrochemical stripping techniques still attract considerable attention for trace metal analysis and for measuring several important organic compounds, due to their unique capabilities of pre-concentrating the analytes at the electrode surface and associated favourable low limits of detection. In this work it is reported for the first time that the Ti(N0,1C0,9), Ti(N0,4C0,6) and Ti(N0,5C0,5) working disc electrodes, a „mercury-free” sensors, offers surprisingly good analytical performance and some valuable properties. The analytical applicability of the Ti(N,C) electrode was confirmed in determination of lead(II) traces in synthetic solutions both with and without surfactants, in certified reference material and in natural water samples. The effects of dissolved oxygen, acids, anions and metal ions were investigated for the Ti(N,C) electrode. Newly prepared and not activated electrode usually cannot be polarized. Therefore, to use the electrode as a voltammetric sensor, its electrochemical activation is required. Composition of conditioning electrolyte and procedures of the electrodes activation were optimized. The fabrication and the response performance of the investigated electrodes were described in the paper. The voltammetric data were associated with the structural characterization of the electrode surface using scanning electron microscopy (SEM) and transmition electron microscopy (TEM).

scholarly journals New sorbents for electrochromatography based on polymer-inorganic dielectric composites

2021 ◽  
Vol 2103 (1) ◽  
pp. 012124
Author(s):  
A Y Shmykov ◽  
S V Mjakin ◽  
N A Bubis ◽  
L M Kuztetzov ◽  
N A Esikova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Filler Content ◽  
Structural Features ◽  
Polymer Binder ◽  
Dielectric Losses ◽  
Infinite Cluster ◽  
Confocal Scanning ◽  
Scanning Electron

Abstract Oligomeric diisocyanate based coatings with different contents of barium titanate (BaTiO3) submicron sized particles as a ferroelectric filler are synthesized on poly(dimethylsiloxane) (PDMS) supports. The study of thus obtained coatings using confocal scanning electron microscopy allowed the characterization of their morphology and features of BaTiO3 particles distribution in the polymer binder, including the determination of threshold filler contents corresponding to the formation of an infinite cluster, matrix-island and chain-like structures as well as the percolation. Dielectric permittivity and dielectric losses of the composites are measured and studied depending on BaTiO3 filler content and relating structural features.

scholarly journals Microfabricated Au-Film Sensors for the Voltammetric Determination of Hg(II)

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1518
Author(s):  
Maria Tsetsoni ◽  
Eleni Roditi ◽  
Christos Kokkinos ◽  
Anastasios Economou
Keyword(s):  
Electrode Surface ◽  
Limit Of Detection ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Voltammetric Determination ◽  
Film Sensor ◽  
Au Film ◽  
Working Electrode ◽  
Anodic Stripping

In this work, a microfabricated Au-film sensor was designed and fabricated for thevoltammmetric determination of Hg(II). The electrode was fabricated on a silicon chip with astandard microengineering approach utilizing photolithography for patterning the electrode shapeand sputtering for deposition of thin Cr and Au films on the surface of the sensors. The sensorswere used for the determination of trace Hg(II) with anodic stripping voltammetry (ASV): initiallyHg(II) in the sample was accumulated on the Au working electrode surface by reduction andformation of an Au(Hg) amalgam followed by oxidation of the preconcentrated metallic Hg using asquare wave voltammetric scan. The limit of detection was 1.5μgL−1 and the coefficient of variationof 10 consecutive measurements was 3.1%.

Structure Determination of Clusters Formed in Ultra-Low Energy High-Dose Implanted Silicon

2005 ◽  
Vol 108-109 ◽  
pp. 303-308 ◽  
Author(s):  
N. Cherkashin ◽  
Martin J. Hÿtch ◽  
Fuccio Cristiano ◽  
A. Claverie
Keyword(s):  
Electron Microscopy ◽  
Geometric Phase ◽  
Low Energy ◽  
High Dose ◽  
Dislocation Loops ◽  
Weak Beam ◽  
Transmission Electron ◽  
Geometric Phase Analysis

In this work, we present a detailed structural characterization of the defects formed after 0.5 keV B+ implantation into Si to a dose of 1x1015 ions/cm2 and annealed at 650°C and 750°C during different times up to 160 s. The clusters were characterized by making use of Weak Beam and High Resolution Transmission Electron Microscopy (HRTEM) imaging. They are found to be platelets of several nanometer size with (001) habit plane. Conventional TEM procedure based on defect contrast behavior was applied to determine the directions of their Burger’s vectors. Geometric Phase Analysis of HRTEM images was used to measure the displacement field around these objects and, thus, to unambiguously determine their Burger’s vectors. Finally five types of dislocation loops lying on (001) plane are marked out: with ] 001 [1/3 ≅ b and b ∝ [1 0 1], [-1 0 1], [0 1 1], [0 -1 1].

Characterization of NiFe2O4 nanoparticles synthesized by various methods

2009 ◽  
Vol 63 (4) ◽  
Author(s):  
Hüseyin Kavas ◽  
Nermin Kasapoğlu ◽  
Abdülhadi Baykal ◽  
Yüksel Köseoğlu
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Process ◽  
Synthesis Method ◽  
Uncoated Sample ◽  
Spin Resonance ◽  
Nife2o4 Nanoparticles ◽  
Sample Method ◽  
First Time ◽  
Hydrothermal Methods

AbstractMicrowave-induced combustion with glycine, CTAB-assisted hydrothermal process with NaOH and NH3, EDTA assisted-hydrothermal methods have been applied to prepare NiFe2O4 nanoparticles for the first time. Structural and magnetic properties of the products were investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmison electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and electron spin resonance spectrometry (EPR). TEM measurements showed that morphology of the product depends on the synthesis method employed. The average cystallite size of NiFe2O4 nanoparticles was in the range of 14–59 nm as measured by XRD. The uncoated sample (Method A) had an EPR linewidth of 1973 Oe, the coated samples reached lower values. The magnetic dipolar interactions existing among the Ni ferrite nanoparticles are reduced by the coatings, which could cause the decrease in the linewidth of the EPR signals. Additionally, the linewidth increases with an increase in the size and the size distribution of nanoparticles.

scholarly journals Microscopic methods in analysis of submicron phospholipid dispersions

2016 ◽  
Vol 66 (1) ◽  
pp. 1-22 ◽  
Author(s):  
Marcin Płaczek ◽  
Magdalena Kosela
Keyword(s):  
Electron Microscopy ◽  
Pharmaceutical Formulations ◽  
Drug Dosage ◽  
Dosage Forms ◽  
Drug Formulation ◽  
Specific Drug ◽  
Pharmaceutical Technology ◽  
Microscopic Techniques

Abstract Microscopy belongs to the group of tests, used in pharmaceutical technology, that despite the lapse of time and the development of new analytical methods, still remain irreplaceable for the characterization of dispersed drug dosage forms (e.g., suspensions and emulsions). To obtain complete description of a specific drug formulation, such as parenteral colloidal products, a combination of different microscopic techniques is sometimes required. Electron microscopy methods are the most useful ones; however, even such basic methods as optical microscopy may be helpful for determination of some properties of a sample. The publication explicates the most popular microscopical techniques used nowadays for characterization of the morphology of nanoparticles suspended in pharmaceutical formulations; ad vantages and disadvantages of these methods are also discussed. Parenteral submicron formulations containing lecithin or a particular phospholipid were chosen as examples.

scholarly journals Synthesis and characterization of four new lanthanide complexes coordinate with β-diketone ligands and 1,10-phenanthroline or 2,2-dipyridine

2020 ◽  
Vol 9 (11) ◽  
pp. e45791110207
Author(s):  
Yuri Johann Vilar de Brito ◽  
Crislene Rodrigues da Silva Morais ◽  
Yohanna Jamilla Vilar de Brito ◽  
Daniella Cibele Bezerra
Keyword(s):  
Electron Microscopy ◽  
Lanthanide Complexes ◽  
Synthesis And Characterization ◽  
Direct Reaction ◽  
Scanning Calorimetry ◽  
Solubility Test ◽  
Microscope Images ◽  
Scanning Electron

In this work the complexes Ln(β-dik)3L (where Ln= Nd+3 e Er+3, β-dik= 4,4,4-trifluoro-1-phenyl-1,3-butanedione (Btfa) and L= 1,10-Phenanthroline (Phen) or 2,2’-Bipyridyl (Bipy)), were synthesized from the direct reaction of LnCl3 with β-diketone and the ligands. The purpose was to create new lanthanide complexes with perspectives of use in markers. After the syntheses, the complexes were characterized by Solubility Test, Scanning Electron Microscopy (SEM) and the thermal properties of compounds were studied using Thermogravimetry Analisys (TGA), Differential Scanning Calorimetry (DSC) and Determination of Melting/Decomposition Intervals. Based on the verified properties, the solubility test found that the complexes are not soluble in chloroform and water. The microscope images showed an excellent crystallization of the complexes. The complexes are stable up to 120°C, after this temperature they show a peak in the DSC referring to the fusion and the beginning of decomposition. The values of activation energy suggests the following decreasing order of stability: Er(Btfa)3Phen>Nd(Btfa)3Phen>Er(Btfa)3Bipy>Nd(Btfa)3Bipy.

scholarly journals Electrochemical deposition and characterization of AgPd alloy layers

2018 ◽  
Vol 83 (5) ◽  
pp. 593-609 ◽  
Author(s):  
Nevenka Elezovic ◽  
Piotr Zabinski ◽  
Mila Krstajic-Pajic ◽  
Tomasz Tokarski ◽  
Borka Jovic ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Convective Diffusion ◽  
Linear Sweep Voltammetry ◽  
X Ray ◽  
Stationary Diffusion ◽  
Current Densities ◽  
Predicted Values ◽  
Disc Electrodes ◽  
First Time

The AgPd alloys were electrodeposited onto Au and glassy carbon disc electrodes from the solution containing 0.001 mol dm-3 PdCl2 + 0.04 mol dm-3 AgCl + 0.1 mol dm-3 HCl + 12 mol dm-3 LiCl under the non-stationary diffusion (quiescent electrolyte) and convective diffusion (? = 1000 rpm) to the different amounts of charge and at different current densities. Electrodeposited alloy layers were characterized by the anodic linear sweep voltammetry (ALSV), scanning electron microscopy, energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The compositions of the AgPd alloys determined by the EDS were almost identical to the theoretically predicted ones, while the compositions obtained by XPS and ALSV analysis were similar to each other, but different from those obtained by EDS. Deviation from the theoretically predicted values (determined by the ratio jL(Pd)/j(Ag)) was more pronounced at lower current densities and lower charges of AgPd alloys electrodeposition, due to the lower current efficiencies for alloys electrodeposition. The ALSV analysis indicated the presence of Ag and Pd, expressed by two ALSV peaks, and in some cases the presence of the additional peak, which was found to correspond to the dissolution of large AgPd crystals, formed at thicker electrodeposits (higher electrodeposition charge), indicating, for the first time, that besides the phase structure, the morphology of alloy electrodeposit could also influence the shape of the ALSV response. In addition to Ag and Pd, the XPS analysis confirmed the presence of AgCl at the surface of samples electrodeposited to low thicknesses (amounts of charge).

Facile Fabrication and Characterization of Carbon Fiber Microelectrode

2011 ◽  
Vol 287-290 ◽  
pp. 1433-1436
Author(s):  
Zhan Jun Yang ◽  
Yan Yan Ren ◽  
Juan Li ◽  
Xiao Ya Hu
Keyword(s):  
Electron Microscopy ◽  
Carbon Fiber ◽  
Electrochemical Behaviors ◽  
Carbon Fiber Microelectrode ◽  
Facile Fabrication ◽  
Fabrication And Characterization ◽  
Carbon Fiber Microelectrodes ◽  
Novel Strategy ◽  
First Time

A novel strategy was proposed to fabricate carbon fiber microelectrodes (CFMEs). The resultant CFMEs were characterized using scan electron microscopy (SEM) and cyclic voltammetry (CV). Compared to the conventional method, the proposed method only needs a simple heating step for achieving CFMEs without additional pulled, sealed and back-filled procedure. The electrochemical behaviors of 2,4-Dichlorophenol (2,4-DCP) at fabricated CFMEs in pH (2.0-9.0) was for the first time studied and demonstrated a two-charge and two-proton transference process.

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