prikaz prve stranice dokumenta Elektrokemijsko ponašanje kofeinske kiseline na ugljikovim nanomaterijalima: prilog optimizaciji elektroanalitičkih metoda određivanja prirodnih reducensa
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master's thesis
Elektrokemijsko ponašanje kofeinske kiseline na ugljikovim nanomaterijalima: prilog optimizaciji elektroanalitičkih metoda određivanja prirodnih reducensa
diplomski rad
Split: University of Split, Faculty of Chemistry and Technology, 2020. urn:nbn:hr:167:719106
Boban, Ana
University of Split
Faculty of Chemistry and Technology
Division of Chemistry

Institutional repository: Repository of the Faculty of chemistry and technology

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Boban, A. (2020). Elektrokemijsko ponašanje kofeinske kiseline na ugljikovim nanomaterijalima: prilog optimizaciji elektroanalitičkih metoda određivanja prirodnih reducensa : diplomski rad (Master's thesis). Split: University of Split, Faculty of Chemistry and Technology. Retrieved from https://urn.nsk.hr/urn:nbn:hr:167:719106

Boban, Ana. "Elektrokemijsko ponašanje kofeinske kiseline na ugljikovim nanomaterijalima: prilog optimizaciji elektroanalitičkih metoda određivanja prirodnih reducensa : diplomski rad." Master's thesis, University of Split, Faculty of Chemistry and Technology, 2020. https://urn.nsk.hr/urn:nbn:hr:167:719106

Boban, Ana. "Elektrokemijsko ponašanje kofeinske kiseline na ugljikovim nanomaterijalima: prilog optimizaciji elektroanalitičkih metoda određivanja prirodnih reducensa : diplomski rad." Master's thesis, University of Split, Faculty of Chemistry and Technology, 2020. https://urn.nsk.hr/urn:nbn:hr:167:719106

Boban, A. (2020). 'Elektrokemijsko ponašanje kofeinske kiseline na ugljikovim nanomaterijalima: prilog optimizaciji elektroanalitičkih metoda određivanja prirodnih reducensa : diplomski rad', Master's thesis, University of Split, Faculty of Chemistry and Technology, accessed 08 November 2024, https://urn.nsk.hr/urn:nbn:hr:167:719106

Boban A. Elektrokemijsko ponašanje kofeinske kiseline na ugljikovim nanomaterijalima: prilog optimizaciji elektroanalitičkih metoda određivanja prirodnih reducensa : diplomski rad [Master's thesis]. Split: University of Split, Faculty of Chemistry and Technology; 2020 [cited 2024 November 08] Available at: https://urn.nsk.hr/urn:nbn:hr:167:719106

A. Boban, "Elektrokemijsko ponašanje kofeinske kiseline na ugljikovim nanomaterijalima: prilog optimizaciji elektroanalitičkih metoda određivanja prirodnih reducensa : diplomski rad", Master's thesis, University of Split, Faculty of Chemistry and Technology, Split, 2020. Available at: https://urn.nsk.hr/urn:nbn:hr:167:719106

Metadata
TitleElektrokemijsko ponašanje kofeinske kiseline na ugljikovim nanomaterijalima: prilog optimizaciji elektroanalitičkih metoda određivanja prirodnih reducensa : diplomski rad
Title (english)Electrochemical behavior of caffeic acid on carbon nanomaterials: a contribution to the optimization of electroanalytical methods for determination of natural reducers : diploma thesis
AuthorAna Boban
MentorMarijo Buzuk (mentor)
Committee memberNives Vladislavić (predsjednik povjerenstva)
Committee memberMaša Buljac (član povjerenstva)
Committee memberMarijo Buzuk (član povjerenstva)
GranterUniversity of Split
Faculty of Chemistry and Technology
(Division of Chemistry)
Split
Defense date and country2020-10-28, Croatia
Scientific / art field,
discipline and subdiscipline		NATURAL SCIENCES
Chemistry
Abstract
U ovom radu su predstavljeni rezultati istraživanja ponašanja kofeinske kiseline na različito modificiranim elektrodama od staklastog ugljika. Elektrokemijska ispitivanja su vršena u tri različite puferske otopine (acetetnom, otopini model vina, Britton-Robinson puferu) te pri različitim pH vrijednostima (2,6 – 3,6 u Britton-Robinson puferu). Uočena je znatna ovisnost elektrokemijskog ponašanja kofeinske kiseline na modificiranim elektrodama u ovisnosti o puferu u kojima su mjerenja vršena. Kao najpogodniji pufer pokazao se Britton-Robinson pufer, dok su značajna kinetička ograničenja zabilježena u acetatnom pufer. Ove pojave su pripisane Frumkinovom efektu, koji je posebno naglašen na elektrodama modificiranim s ugljikovim nanocijevčicama. Nadalje, kinetička ograničenja vezana za prijenos elektrona kroz heterogenu granicu faza ispitivana su u širokom području brzina posmika. Na osnovu analize izračunati su koeficijenti prijelaza (α), kao i konstante brzine prijenosa elektrona za sve modificirane elektrode i u svim puferima. Povišenjem pH vrijednosti dolazi do pomaka potencijala strujnih pikova, ali i do smanjenja osjetljivosti. Ove pojave objašnjene su u kontekstu predloženih mehanizama oksidacije/redukcije kofeinske kiseline. Kao najoptimalniji sustav za određivanje kofeinske kiseline, na osnovu analize, isprofilirale su se elektrode modificirane ugljikovim nanocijevčicama u Britton-Robinson puferu, pri pH 3,6. Rezultati ovog diplomskog rada, zajedno s rezultatima dobivenim s drugim polifenolima na istim elektrodama mogu pomoći u prevladavanju interferencija, povećanju osjetljivosti i razvoju nove metode za određivanje polifenola u realnim uzorcima.
Abstract (english)
This graduate thesis presents the results of research on the behavior of caffeic acid on variously modified glassy carbon electrodes. Electrochemical tests were performed in three different buffer solutions (acetate, wine model solution, Britton-Robinson buffer) at different pH values (2,6 – 3,6 in Britton-Robinson buffer). A significant dependence of the electrochemical behavior of caffeic acid on the modified electrodes was observed depending on the buffer in which the measurements were performed. Britton-Robinson buffer proved to be the most suitable buffer, while significant kinetic limitations were noted in acetate buffer. These phenomena are attribute to Frumkin effect, which is particularly pronounced on electrodes modified with carbon nanotubes. Furthermore, the kinetic constraints related to electron transfer across the heterogeneous phase boundary were investigated over a wide range of scan rates. Based on the analyses, the transition coefficients (α), and constant electron transfer rates for all modified electrodes in all buffers were calculated. Increasing the pH value shifts the potential of current peaks, but also reduces the sensitivity These phenomena are explained in the context of the proposed mechanisms of oxidation / reduction of caffeic acid. Based on analyses most optimal system for the determination of caffeic acids are modified electrodes with carbon nanotubes in Britton-Robinson buffer, at pH 3,6. The results of this thesis, together with the results obtained with other polyphenols on the same electrodes can help to overcome interference, increase sensitivity and develop new methods for the determination of polyphenols in real samples.
Keywords
Keywords (english)
Languagecroatian
URN:NBNurn:nbn:hr:167:719106
Study programmeTitle: Chemistry; specializations in: Environmental Protection, Organic Chemistry and Biochemistry
Course: Environmental Protection
Study programme type: university
Study level: graduate
Academic / professional title: magistar/magistra kemije (magistar/magistra kemije)
Type of resourceText
File originBorn digital
Access conditionsOpen access
Terms of useLicence In copyright icon
Created on2020-12-11 07:22:39