Effect of cetyltrimethylammonium bromide on the electrochemiluminiscence and electrooxidation of luminol

1983 ◽  
Vol 48 (2) ◽  
pp. 477-483 ◽  
Author(s):  
Jan Lasovský ◽  
František Grambal
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Linear Sweep Voltammetry ◽  
Critical Micellar Concentration ◽  
Peak Height ◽  
Anodic Peak ◽  
Alkaline Solutions ◽  
Platinum Electrodes ◽  
Micellar Solutions ◽  
Linear Sweep ◽  
Low Concentrations

The electrooxidation of luminol in alkaline solutions in the presence of cetyltrimethylammonium bromide (I) was studied by linear sweep voltammetry on fixed and vibrating platinum electrodes. The presence of I in low concentrations (below the critical micellar concentration) brings about aggregation of the luminol, which is manifested by an increase in the anodic peak height and its shift towards lower potentials. In micellar solutions the peak height decreases owing to the slower diffusion of the bulkier micelles, the shift to lower potentials being preserved. The light-voltage curves correspond with the voltammetric curves, exhibiting identical shifts of the peak potentials in dependence on the concentration of the surfactant.

Electron Transfer in Electro-Oxidation of Amoxicillin Using Platinum Electrode and Platinum Modified Cobalt Electrodes

2021 ◽  
Vol 874 ◽  
pp. 155-164
Author(s):  
Herlina ◽  
Muhammad Ali Zulfikar ◽  
Buchari
Keyword(s):  
Electron Transfer ◽  
Oxidation Process ◽  
Platinum Electrode ◽  
Linear Sweep Voltammetry ◽  
Pharmaceutical Product ◽  
Electrochemical Methods ◽  
Linear Sweep ◽  
Low Concentrations ◽  
Electro Oxidation ◽  
Continuous Use

Recently, the increased use of antibiotics in the environment has been studied and one of them is amoxicillin. Amoxicillin (AMX) is a pharmaceutical product that can become waste due to the continuous use and released into the ecosystem even at low concentrations. The electro-oxidation process is one of the electrochemical methods used to destruct the existence of antibiotics because the process is relatively fast and inexpensive. Platinum electrode and platinum modified cobalt electrodes are used for amoxicillin electro-oxidation at the pH of 2 - 7. The range of this amoxicillin's pH was achieved by the pKa's values of the amoxicillin and measured using a UV/Vis spectrophotometer. Electron transfer during the amoxicillin electro-oxidation process with these electrodes is measured by linear sweep voltammetry. The results obtained during the electro-oxidation process showed that electron transfer of amoxicillin was 1, with a Nernstian factor of 0.0521 V/pH for platinum electrode and platinum modified cobalt electrodes, Pt/Co(OH)2 and Pt/Co respectively with values of 0.0506 V/pH and 0.0673 V/pH.

scholarly journals Determination of the zinc and cadmium contents in low-alloyed tin

1999 ◽  
Vol 64 (11) ◽  
pp. 707-720
Author(s):  
N.Z. Blagojevic ◽  
R.M. Zejnilovic ◽  
A.R. Despic ◽  
Z. Blecic
Keyword(s):  
Thin Layer ◽  
Solid Solutions ◽  
Analytical Methods ◽  
Linear Sweep Voltammetry ◽  
Sweep Rate ◽  
Eutectic Type ◽  
Linear Sweep ◽  
Low Concentrations ◽  
Non Destructive

The method of anodic linear sweep voltammetry (ALSV) has been used to determine the content of Zn and Cd (up to 4% w/w) in eutectic type binary alloys with Sn. The alloy samples were prepared by casting. The effect of the type and the pH of the electrolyte, as well as of the sweep-rate on the dissolution of Zn and Cd from the alloy during an anodic potentinal-sweep was investigated. It was shown that ALSV is sensitive to low concentrations of both Zn and Cd in the investigated alloys, as well-defined peaks of the dissolution of the two metals were recorded before the massive dissolution of Sn commenced. Well-defined linear dependencies between the quantities of electricity under the dissolution peaks of Zn (QZn) or Cd (QCd) and the respective contents of the metals in the alloys were found. Intercepts at the abscissa were found in both investigated systems indicating the formation of solid solutions from which neither Zn norCd could be eluted. In both alloys, the smallest amount of the alloying component which could be detected was 0.25% (w/w). The application of the ALSV method has several advantages over other analytical methods: it is non-destructive as the dissolution involves only a very thin layer of the alloy; it requires simple and cheap instrumentation; it is fast and relatively sensitive. These make it suitable for routine analysis.

scholarly journals An Electrochemical Route for Hot Alkaline Blackening of Steel: A Nitrite Free Approach

Surfaces ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 216-228 ◽  
Author(s):  
Maximilian Eckl ◽  
Steve Zaubitzer ◽  
Carsten Köntje ◽  
Attila Farkas ◽  
Ludwig Kibler ◽  
...  
Keyword(s):  
Linear Sweep Voltammetry ◽  
Bath Temperature ◽  
Alkaline Solutions ◽  
Linear Sweep ◽  
Dc Voltage ◽  
Force Microscopy ◽  
Protective Layers ◽  
Slope Analysis ◽  
Atomic Force ◽  
Steel Surfaces

Blackening belongs to the predominant technological processes in preserving steel surfaces from corrosion by generating a protective magnetite overlayer. In place of the commonly used dipping-procedure into nitrite-containing blackening baths at boiling temperatures that are far above 100 °C, here we describe a more environmentally friendly electrochemical route that operates at temperatures, even below 100 °C. After an investigation of the electrochemical behavior of steel samples in alkaline solutions at various temperatures, the customarily required bath temperature of more than 130 °C could be significantly lowered to about 80 °C by applying a DC voltage that leads to an electrode potential of 0.5−0.6 V vs. Pt. Thus, it was possible to eliminate the use of hazardous sodium nitrite economically and in an optimum way. Electrochemical quantification of the corrosion behavior of steel surfaces that were in contact with 0.1 M KCl solution was carried out by linear sweep voltammetry and by Tafel slope analysis. When comparing these data, even the corrosion rates of conventional blackened surfaces are of the same magnitude as a blank steel surface. This proves that magnetite overlayers represent rather poor protective layers in the absence of additional sealing. Moreover, cyclic voltammetry (CV), atomic force microscopy (AFM), scanning electron microscopy (SEM) and auger electron spectroscopy (AES) characterized the electrochemically blackened steel surfaces.

scholarly journals Electrochemical Approaches for Rapid Characterization of Oxidizable Compounds in Different Oak Alternatives

Beverages ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 1
Author(s):  
Jéremie Wirth ◽  
Davide Slaghenaufi ◽  
Stéphane Vidal ◽  
Maurizio Ugliano
Keyword(s):  
Linear Sweep Voltammetry ◽  
Wine Industry ◽  
Wine Aroma ◽  
Total Current ◽  
Strong Correlations ◽  
Tannin Content ◽  
Linear Sweep ◽  
Antioxidant Characteristics ◽  
Rapid Characterization

Oak alternatives (OAs) such as chips, granulates or staves, are becoming increasingly used in the wine industry. Although they are mostly considered for their contribution to wine aroma, they are also a source of phenolic compounds to be released in the wine, in particular ellagitannins contributing to wine mouthfeel and antioxidant characteristics. In the present study, we explore the potential for a rapid analytical method based on linear sweep voltammetry (LSV) combined with disposable sensors to provide a rapid measure of the oxidizable compounds present in different OAs, as well as their characterization. Strong correlations were found between the tannin content of different OAs and the total current measures during LSV analysis, allowing a rapid quantification of the oxidizable compounds present, mostly ellagitannin. Application of derivatization to raw voltammograms allowed extraction of a number of features that can be used for classification purposes, in particular with respect to OAs types (chips or staves) and degree of toasting.

scholarly journals NADPH-dependent reduction of 2,6-dichlorophenol-indophenol by the phagocytic vesicles of pig polymorphonuclear leucocytes

1983 ◽  
Vol 210 (2) ◽  
pp. 577-581 ◽  
Author(s):  
H Wakeyama ◽  
K Takeshige ◽  
S Minakami
Keyword(s):  
Oxidation Rate ◽  
Cetyltrimethylammonium Bromide ◽  
Reductase Activity ◽  
Tween 20 ◽  
Polymorphonuclear Leucocytes ◽  
Resting Cells ◽  
Low Concentrations ◽  
Km Value ◽  
Nadph Oxidation

NADPH-dependent 2,6-dichlorophenol-indophenol (DCIP) reductase activity in the homogenate of phagocytosing pig polymorphonuclear leucocytes was twice that of the resting cells and the activity in the phagocytic vesicles corresponded to the activity increment due to phagocytosis. The apparent Km value of the reductase activity in the vesicles for NADPH was 30 microM, which is similar to that of the NADPH-dependent superoxide (O2-) formation. Increasing the DCIP reductase activity by increasing the DCIP concentration caused a decrease in the O2- –forming activity, the NADPH oxidation rate being constant and independent of the dye concentration. p-Chloromercuribenzoate and cetyltrimethylammonium bromide at low concentrations inhibited the O2- –forming activity of the vesicles without inhibiting the DCIP reductase. Quinacrine inhibited both O2- formation and DCIP reduction. The DCIP reductase activity could be extracted with a mixture of deoxycholate and Tween-20, which extracts the O2- –forming activity. The reductase activity in the extract was enhanced 2-fold by the addition of FAD, and its apparent Km was 0.085 microM. These results indicate that the NADPH-dependent DCIP reductase activity of the phagocytic vesicles is catalysed by a flavin-containing component of the O2- –forming system.

The cathodic reduction of PbO in the passive layer on lead in aqueous sulphuric acid

1984 ◽  
Vol 62 (3) ◽  
pp. 596-600 ◽  
Author(s):  
R. G. Barradas ◽  
D. S. Nadezhdin
Keyword(s):  
Experimental Data ◽  
Three Dimensional ◽  
Reference Electrode ◽  
Linear Sweep Voltammetry ◽  
Passive Layer ◽  
Cathodic Reduction ◽  
Linear Sweep ◽  
Current Time ◽  
Lead Monoxide ◽  
Two Peaks

The cathodic reduction of the lead monoxide layer formed on lead in 30% aqueous H2SO4 under anodic oxidation at 0.6 V (vs. Hg/HgSO4 reference electrode) was investigated by linear sweep voltammetry, potential step and admittance measurements. The experimental data were analyzed respectively in terms of thin-layer electrochemistry, electrocrystallisation, and changes of resistance of the PbO layer under reduction. The results seem to be best interpreted from the theory of three-dimensional electrocrystallisation as PbO is reduced to Pb. At sub-zero temperatures the PbO peak observed on our voltammograms and potentiostatic current time transients reveals the splitting of the curves into two peaks, which may be a result of reduction of the same material but of different phases, namely, orthorhombic and tetragonal PbO.

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