Adsorption and Oxidation of Thiosulfate on a Platinum Electrode in Acid Solution

1998 ◽  
Vol 63 (1) ◽  
pp. 20-30 ◽  
Author(s):  
Tomáš Loučka
Keyword(s):  
Open Circuit Potential ◽  
Platinum Electrode ◽  
Supporting Electrolyte ◽  
Open Circuit ◽  
Adsorbed Layers ◽  
Adsorbed Substance ◽  
Adsorbed Sulfur ◽  
Adsorption Desorption ◽  
Supporting Electrolyte Solution ◽  
Thiosulfate Concentration

The adsorption of thiosulfate on a platinum electrode was measured at the open circuit potential. A monolayer of the adsorption products covers the electrode at lower thiosulfate concentrations. The charge used up during the reduction of the monolayer roughly corresponds to 0.5 electron per surface site (e.p.s.), the charge used up during the oxidation of the monolayer after reduction corresponds approximately to 4 e.p.s. Multiple adsorbed layers, which are presumably constituted mainly by adsorbed sulfur, build up at higher thiosulfate concentrations. The amount of the adsorbed substance increases with increasing thiosulfate concentration and time of adsorption. Desorption from the surface coated by multiple layers can take place in supporting electrolyte solution. The build-up of multiple adsorbed sulfur layers also takes place during adsorption from solutions of colloidal sulfur.

Adsorption and Oxidation of Thiosulfate on the Platinum Electrode in a Slightly Alkaline Medium

2000 ◽  
Vol 65 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Tomáš Loučka
Keyword(s):  
Alkaline Medium ◽  
Oxidation Reaction ◽  
Open Circuit Potential ◽  
Platinum Electrode ◽  
Adsorbed Layer ◽  
Open Circuit ◽  
Adsorbed Hydrogen ◽  
Oxidation Number ◽  
Hydrogen Electrode ◽  
Layer Region

The aim of this research was to study the oxidation and reduction of the adsorbed thiosulfate on the platinum electrode in a slightly alkaline medium. The adsorption was performed at the open circuit conditions. The reduction of the adsorbed layer in the hydrogen region is slower in a slightly alkaline medium than in acid. The mechanism of reduction and oxidation of adsorbed molecules is probably the same. The nonstationary currents measured in presence of thiosulfates showed that the change in the oxidation number does not take place during the adsorption in the double layer region. In the hydrogen region, thiosulfate replaces the adsorbed hydrogen while beeing reduced. Nonstationary currents at higher concentrations of thiosulfate indicate the presence of more layers on the electrode. Upon reaching higher concentrations of thiosulfate the oxidation reaction takes place between thiosulfate in solution and adsorbed product of its reduction. The open circuit potential of the platinum electrode measured in a thiosulfate solution was 0.780 and 0.783 V against the hydrogen electrode in the same solution.

scholarly journals Adsorption characteristics of albumin on gold and titanium metals in Hanks’ solution using EQCM

2004 ◽  
Vol 18 (4) ◽  
pp. 545-552 ◽  
Author(s):  
J. A. Lori ◽  
T. Hanawa
Keyword(s):  
Bovine Serum Albumin ◽  
Quartz Crystal Microbalance ◽  
Quartz Crystal ◽  
Open Circuit Potential ◽  
Electrochemical Quartz Crystal Microbalance ◽  
Open Circuit ◽  
Rest Potential ◽  
Before And After ◽  
Titanium Surfaces ◽  
Adsorption Desorption

The adsorption of Bovine Serum Albumin (BSA) on gold and titanium surfaces in Hanks’ solution was monitored using the electrochemical quartz crystal microbalance (EQCM) technique. The changes in mass and open circuit potential at rest potential and mass and current at constant potentials were measured before and after the introduction of BSA.The mass of BSA adsorbed on titanium reached a steady value within one hour, while the albumin adsorbed on gold continued to increase. The amount of BSA adsorbed by titanium increased with concentration and stabilized at 0.8 mg/ml while that on gold did not stabilize. This indicates a monolayer of the protein on titanium and multi-layer on gold. The adsorption of BSA on gold and titanium was accelerated by the charge of potential.The time before stabilizing the adsorption‒desorption phenomena also increased with the BSA concentration.

scholarly journals Diagnostic capabilities of monitoring of redox potential in blood plasma of lung transplant patients

2019 ◽  
Vol 11 (2) ◽  
pp. 128-140 ◽  
Author(s):  
A. K. Evseev ◽  
E. I. Pervakova ◽  
I. V. Goroncharovskaya ◽  
E. A. Tarabrin ◽  
M. Sh. Khubutiya ◽  
...  
Keyword(s):  
Blood Plasma ◽  
Lung Transplant ◽  
Open Circuit Potential ◽  
Clinical Laboratory ◽  
Platinum Electrode ◽  
Open Circuit ◽  
Transplant Patients ◽  
Laboratory Test Results ◽  
Diagnostic Capabilities ◽  
In Blood Plasma

Introduction. Monitoring of redox potential (platinum electrode open circuit potential) in biological media (serum, blood plasma) is one of the promising methods for diagnosing and predicting the development of complications in patients in the early post-transplantation period. The study of the diagnostic capabilities of this technique in patients after lung transplantation is highly relevant.The objective was to assess the diagnostic and prognostic capabilities of monitoring platinum electrode open circuit potential in blood plasma of lung transplant patients.Material and methods. The data obtained at monitoring of platinum electrode open circuit potential in blood plasma and clinical laboratory test results of 14 patients after double lung transplantation surgery were analyzed. The platinum electrode open circuit potential value in the blood plasma was measured by the potentiometric method.Results. The study demonstrated the differences in the dynamics and values of platinum electrode open circuit potential in the blood plasma between the lung transplant patients with a favorable outcome and those with a fatal outcome. Wave-like segments on the relationship curves of the platinum electrode open circuit potential in blood plasma to time coincided with inflammatory markers (C-reactive protein, stab neutrophils, erythrocyte sedimentation rate) activation. Statistically significant correlations between platinum electrode open circuit potential values in blood plasma and clinical laboratory test results were revealed.Conclusion. The informative value and diagnostic capabilities of the technique of the platinum electrode open circuit potential measurement in blood plasma of lung transplant patients have prospects of using its results as a criterion for assessing the patient’s condition and improving the quality of therapy. 

INTERRELATION OF PLATINUM ELECTRODE OPEN CIRCUIT POTENTIAL IN THE BLOOD PLASMA AND OXIDATIVE STRESS COEFFICIENT IN PATIENTS WITH ACUTE POISONING BY CAUTERANT AGENTS

2018 ◽  
pp. 7-12
Author(s):  
М. М. Potskhveriya ◽  
A. K. Evseev ◽  
A. Yu. Simonova ◽  
E. V. Klychnikova ◽  
I. V. Goroncharovskaya ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Activity ◽  
Blood Plasma ◽  
Open Circuit Potential ◽  
Platinum Electrode ◽  
Acute Poisoning ◽  
Open Circuit ◽  
Total Antioxidant Activity ◽  
Stress Coefficient ◽  
Total Antioxidant

The relationship between the platinum electrode open circuit potential (OCP) in the blood plasma as an integral indicator of the balance of oxidation-reduction processes in the body with an oxidative stress coefficient (K) reflecting the balance of the lipid peroxidation and state of antioxidant system (LPO/AOS) in patients with acute poisoning by cauterant agents was investigated. The platinum electrode OCP in the blood plasma was measured using an original electrochemical technique. The oxidative stress coefficient was determined from the ratio of the malondialdehyde level to the total antioxidant activity of blood serum. The shift of the value of the platinum electrode OCP in blood plasma during the first 5-7 days towards the positive potential region coincided with the intensification of LPO processes and the decrease in total antioxidant activity of the blood serum. Sharp shift in the value of the platinum electrode OCP to the region of positive values (more than 25 mV) in patients with acute poisoning with cauterant agents coincides with the worsening of their condition. The data obtained during the monitoring of the platinum electrode OCP in blood plasma in patients with acute poisoning by cauterant agents allow to make a conclusion about the diagnostic capabilities of this technique for assessing the patient’s severity and correcting his treatment.

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