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Electrochemical sensor with electrode modified by phthalocyanine derivative used for determination of sulfur compounds
Zlámalová, Magda ; Nesměrák, Karel (advisor) ; Navrátil, Tomáš (referee)
The diploma thesis presents the results of the studies of thin layer film composed of N,N',N'',N'''-tetramethyl-tetra-3,4-pyridinoporphyrazinocobalt. This film is deposited on the surface of highly oriented pyrolytic graphite. The modified electrode displayed electrocatalytic activity to oxidation of sulphide anions and cysteine. It has been studied the possibility of enhancement of stability of the immobilized film by the nafion. This electrode was used for the analytical determination of sulphide anions and cysteine. Keywords: highly oriented pyrolytic graphite, porphyrazines, hydrogen sulphide, cysteine, nafion, cyclic voltammetry, atomic force microscopy
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Comparision of methods for sulphide determination
Zlámalová, Magda ; Nesměrák, Karel (advisor) ; Červený, Václav (referee)
The aim of this work is determination of sulphides in a solution by suitable methods and it's subsequent comparison from a point of view to the precision, financial and time demands. Iodometric titration, argentometric titration, and potassium ferricyanide titration were chosen for the determination of sulphides in the solution. Anhydrous sodium sulphide and sodium sulphide hydrate were used as model samples. From the point of view to financial and time demands the most advantageous method was potassium ferricyanide titration and the least advantageous method was iodometric titration. The precision of used methods was dependent on type of used sample. Iodometry was the least precise determination of sulphides in the sample of anhydrous sodium sulphide; the precision of argentometry and potassium ferricyanide titration was comparable. Potassium ferricyanide titration was the most precise determination of sulphides in the sample of sodium sulfide hydrate; the least precise determination was argentometry.
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Development of the poly(methylene blue) modified graphite electrodes for the electrochemical detection of hydrogen sulphide
Zlámalová, Magda ; Janda, Pavel ; Nesměrák, K.
A comparative study have been undertaken of the electropolymerization and electrochemical properties of deposited electroactive polymer on two different graphite electrode substrates: basal plane highly oriented pyrolytic graphite (HOPG) and pencil-graphite electrode (PGE). Poly(methylene blue) modified electrodes (HOPG/pMB and PGE/pMB) have been prepared by potential cycling in aqueous electrolyte solution containing methylene blue monomer. It has been found that electrochemical properties and electrocatalytic activity of deposited film are greatly influenced by the type of electrode substrate. Developed electrodes have been further investigated as potential sensors for hydrogen sulphide.
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Graphite Electrode Modified by Poly(Methylene Blue) and its Electrocatalytic Activity towards Hydrogen Sulfide Oxidation
Zlámalová, Magda ; Janda, Pavel ; Nesměrák, K.
This research is focused on the electrochemical synthesis and characterization of\npoly(methylene blue) (pMB). Two different carbon-based electrode substrates, basal plane\nhighly oriented pyrolytic graphite (HOPG) and pencil graphite electrode (PGE), have been\nmodified by conductive film of pMB. Electrochemical properties and nanomorphological\nchanges have been investigated by cyclic voltammetry and atomic force microscopy.\nImproved electroactivity of the modified electrodes (PGE/pMB and HOPG/pMB) towards\nsulfhydryl group has been observed and examined modified electrodes were researched for\ntheir possible application in electrochemical sensor for hydrogen sulfide in aqueous solutions.
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Electrochemical sensor with electrode modified by phthalocyanine derivative used for determination of sulfur compounds
Zlámalová, Magda ; Nesměrák, Karel (advisor) ; Navrátil, Tomáš (referee)
The diploma thesis presents the results of the studies of thin layer film composed of N,N',N'',N'''-tetramethyl-tetra-3,4-pyridinoporphyrazinocobalt. This film is deposited on the surface of highly oriented pyrolytic graphite. The modified electrode displayed electrocatalytic activity to oxidation of sulphide anions and cysteine. It has been studied the possibility of enhancement of stability of the immobilized film by the nafion. This electrode was used for the analytical determination of sulphide anions and cysteine. Keywords: highly oriented pyrolytic graphite, porphyrazines, hydrogen sulphide, cysteine, nafion, cyclic voltammetry, atomic force microscopy
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Comparision of methods for sulphide determination
Zlámalová, Magda ; Červený, Václav (referee) ; Nesměrák, Karel (advisor)
The aim of this work is determination of sulphides in a solution by suitable methods and it's subsequent comparison from a point of view to the precision, financial and time demands. Iodometric titration, argentometric titration, and potassium ferricyanide titration were chosen for the determination of sulphides in the solution. Anhydrous sodium sulphide and sodium sulphide hydrate were used as model samples. From the point of view to financial and time demands the most advantageous method was potassium ferricyanide titration and the least advantageous method was iodometric titration. The precision of used methods was dependent on type of used sample. Iodometry was the least precise determination of sulphides in the sample of anhydrous sodium sulphide; the precision of argentometry and potassium ferricyanide titration was comparable. Potassium ferricyanide titration was the most precise determination of sulphides in the sample of sodium sulfide hydrate; the least precise determination was argentometry.
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Poly(methylene blue) modified carbon based electrodes for the determination of sulfhydryl-containing compounds
Zlámalová, Magda ; Janda, Pavel ; Nesměrák, K.
This research presents the study of electrochemical polymerization of phenothiazine derivative, methylene blue (MB). Electrochemical pro perties and analytical application of resulting electrocatalytically active poly(methylene blue) (pMB) have been investigated. Three various carbon-based substrates: basal plane of highly oriented pyro lytic graphite (HOPG), pencil graphite electrode (PGE) and carbon fibre micro electrode (CFE) have been used. Aforementioned electrodes modified with the polymer (HOPG/pMB, PGE/pMB and CFE/pMB) have been prepared by potential cycling in aqueous electrolyte solution containing dissolved monomeric methylene blue. Electrocatalytic activity of three developed electrode systems towards hydrogen sulphide has been compared. Developed electrodes have been further investigated as potential sensors for sulfhydryl-containing compounds.
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Poly(Methylene Blue) Modified Carbon-based Electrodes for Electrochemical Detection of Hydrogen Sulfide
Zlámalová, Magda ; Janda, Pavel ; Nesměrák, K.
A comparative electrochemical study has been carried out of the electropolymerization of phenothiazine derivative, methylene blue (MB). Electrochemical properties of resulting electrocatalytically active methylene blue polymer (pMB) have been studied on three various carbon-based substrates: basal plane of highly oriented pyrolytic graphite (HOPG), pencil-graphite electrode (PGE) and carbon fibre micro electrode (CFE). Electrodes modified with the polymer (HOPG/pMB, PGE/pMB and CFE/pMB) have been prepared by potential cycling in aqueous electrolyte solution containing dissolved monomeric methylene blue. Electrocatalytic activity of three developed electrode systems towards hydrogen sulphide has been compared. Developed electrodes have been further investigated as potential sensors for sulfhydryl-containing compounds.
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Electrochemical Characterization of Poly(methylene Blue) Modified Graphite Electrodes
Zlámalová, Magda ; Janda, Pavel ; Nesměrák, K.
This work deals with electrochemical study of methylene blue (MB) polymerization as well as characterization of deposited conductive film on basal plane highly oriented pyrolytic graphite (HOPG) and pencil-graphite electrode (PGE). Poly(methylene blue) modified electrodes (HOPG/pMB and PGE/pMB) have been prepared by potential cycling in aqueous electrolyte solution containing methylene blue monomer. It has been found that electrochemical properties and electrocatalytic activity of deposited film are greatly influenced by the type of electrode substrate. Developed electrodes have been further investigated as potential sensors for sulfhydryl-containing compounds.
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