Title Kompleksi metala i karnozina
Title (english) Metal complexes of carnosine
Author Mateja Drulak
Mentor Martina Medvidović-Kosanović (mentor)
Committee member Elvira Kovač-Andrić (predsjednik povjerenstva)
Committee member Martina Medvidović-Kosanović (član povjerenstva)
Committee member Aleksandar Sečenji (član povjerenstva)
Granter Josip Juraj Strossmayer University of Osijek Department of Chemistry (Department of General, Inorganic and Physical Chemistry and Methodology of Chemistry) Osijek
Defense date and country 2017-12-27, Croatia
Scientific / art field, discipline and subdiscipline NATURAL SCIENCES Chemistry Physical Chemistry
Abstract U ovom radu ispitivana su elektrokemijska i spektrofotometrijska svojstva β-alanina, L-histidina i L-karnozina koncentracije, c = 1∙\( 10^{-4} \) mol \( dm^{-3}\) te stvaranje kompleksa navedenih spojeva s bakrom u omjerima 1:1, 2:1, 4:1, 1:2 i 1:4 u puferu pH = 10. Cilj rada bio je ispitati stvaranje kompleksa β-alanina, L-histidina i L-karnozina s dvovalentnim bakrovim ionom, \( Cu^{2+}\) u puferu pH = 10, odrediti omjer pri kojem nastaju kompleksi, istražiti utjecaj brzine promjene polarizacije elektrode na oksido-redukcijska svojstva kompleksa, istražiti moguću adsorpciju oksidacijskog produkta na površinu radne elektrode. Elektrokemijska svojstva ispitivana su pomoću potenciometrijske titracije te cikličke i diferencijalno pulsne voltametrije, a spektrofotometrijska pomoću UV/VIS spektrofotometrije. Elektrokemijska ćelija za potenciometrijska mjerenja sadržavala je platinsku indikatorsku elektrodu. U otopinu analita (β-alanin, L-histidin ili L-karnozin) dodavala se otopina bakrova nitrata, a završna točka titracije određena je instrumentalno. Za voltametrijska mjerenja koristio se troelektrodni sustav s radnom elektrodom od staklastog ugljika. Potenciometrijskom titracijom utvrđeno je da L-histidin i L-karnozin tvore kompleks s bakrovim ionom u omjeru 1:1 u puferu pH = 10. Ciklička voltametrija pokazala je da β-alanin, L-histidin i L-karnozin nisu elektroaktivni te da dolazi do stvaranja kompleksa između L-histidina i bakrovog iona te L-karnozina i bakrovog iona već u omjeru 1:1 kao i da je proces koji se odvija na površini radne elektrode difuzijski kontroliran. Diferencijalnom pulsnom voltametrijom potvrđeno je nastajanje kompleksa L-histidina i L-karnozina s bakrovim ionom u puferu pH = 10, utvrđeno je da su L-histidin i L-karnozin elektroaktivni te da ne dolazi do adsorpcije L-histidina i L-karnozina te njihovih kompleksa s bakrovim ionom na radnu elektrodu od staklastog ugljika
Abstract (english) In this work electrochemical and spectrometric properties of β-alanine, L-histidine and L-carnosine concentration, c = 1∙\( 10^{-4} \) mol \( dm^{-3}\) as well as complexation of those compounds with copper in ratio 1:1, 2:1, 4:1, 1:2 and 1:4 prepared in buffer pH = 10 were studied. Main purpose of this thesis was to examine complexation of β-alanine, L-histidine and L-carnosine with divalent copper ion, \( Cu^{2+}\) in buffer pH = 10, determine ratio of complexation, investigate influence of the scan rate on the oxido-reduction properties of complexes, study possible adsorption of oxidation product on the surface of the working electrode. Electrochemical properties were investigated by potentiometric titration, cyclic voltammetry and differential pulse voltammetry, while spectrometric with UV/VIS spectrometry. Electrochemical cell for potentiometric measurements was consisted of platinum indicator electrode. Solution of copper nitrite was added in solution of analyte (β-alanine, L-histidine, L-carnosine) and equivalent point was determined instrumentally. Three electrode system with glassy carbon working electrode was used for voltammetric measurements. It was found by potentiometric titration that L-histidine and L-carnosine form complex with copper ion in ratio 1:1 in buffer pH = 10. Cyclic voltammetry showed that β-alanine, L-histidine and L-carnosine were not electroactive and also that there is complexation among L-histidine and copper ion as well as L-carnosine and copper ion from ratio 1:1. Likewise measurements showed that process which undergoes on working electrode is diffusion controlled. Complexation of L-histidine and L-carnosine with copper ion in buffer pH = 10 was confirmed by differential pulse voltammetry as well as that L-histidine and L-carnosine were electroactive and that there was not undergone adsorption of L-histidine, L-carnosine and its complex with copper ion on glassy carbon working electrode.
Keywords
β-alanin / ciklička voltametrija / diferencijalna pulsna voltametrija / L-histidin / L-karnozin / potenciometrijska titracija / UV/VIS spektrofotometrija
Keywords (english)
β-alanine / cyclic voltammetry / differential pulse voltammetry / L-histidine / L-carnosine / potentiometric titration / UV/VIS spectrophotometry
Language croatian
URN:NBN urn:nbn:hr:182:402260
Study programme Title: Graduate University Study of Chemistry; research direction Study programme type: university Study level: graduate Academic / professional title: magistar/magistra kemije (magistar/magistra kemije)
Type of resource Text
File origin Born digital
Access conditions Open access
Terms of use
Created on 2018-02-05 13:02:50