magistrsko delo
Žiga Mlinar (Author), Drago Kočar (Mentor), Iztok Turel (Thesis defence commission member), Mitja Kolar (Thesis defence commission member)

Abstract

Povzetek: V magistrskem delu sem se ukvarjal s študijem Fentonove reakcije in njej podobne reakcije z Fe(III) soljo. Ugotovil sem, da je sol tista, ki ima večji vpliv pri sami razgradnji organskih snovi kot peroksid. Klasična Fentonova reakcija, kjer se uporabljajo Fe2+ ioni je bolj učinkovita pri razgradnji kot Fentonovi podobna reakcija s prisotnimi Fe3+ ioni. Večje koncentracije dvovalentne soli so privedle do večjega razpada preiskovanih analitov. Cl– ioni predstavljajo lovilce hidroksilnih radikalov. Njihov interferenčni vpliv sem dokazoval z dodajanjem različnih koncentracij soli KCl v poskusno mešanico za Fentonovo reakcijo. Pri razpadu kofeina dodatek anionov ne vpliva na obseg razgradnje, medtem ko je pri teofilinu prišlo do ravno obratnega učinka. Skušal sem določiti še red reakcije, a se je izkazalo, da je reakcija neceloštevilskega reda. Reakcija razgradnje je najbolj učinkovita v kislem območju pri pH = 3, pri razgradnji pa nisem uspel detektirati spojin, ki bi absorbirale svetlobo valovnih dolžin do 230 nm, kjer je mejna valovna dolžina ocetne kisline. Tudi v masnih spektrih končne raztopine ni bilo mogoče določiti razgradnih produktov. Na koncu sem določil še pogoje razgradnje pod mejo zaznave HPLC sistema. To so: pH = 3, c(H2O2) = 100 μmol/L in c(Fe2+) = 100 μmol/L.

Keywords

teofilin;kofein;Fentonov reagent;mehanizem razpada organskih onesnaževal;tekočinska kromatografija;masna spektroskopija;HPLC-MS;magistrska dela;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher: [Ž. Mlinar]
UDC: 66.094.3:543.544.5:543.51(043.2)
COBISS: 48042755 Link will open in a new window
Views: 620
Downloads: 110
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Other data

Secondary language: English
Secondary title: Degradation of caffeine and theophylline by Fenton regent in aqueous solutions
Secondary abstract: Abstract: In my master thesis I investigated the Fenton reaction and a similar reaction with Fe(III) salt. I found out that the salt in contrast to the hydrogen peroxide has a greater influence on the decomposition of the organic matter itself. The classical Fenton reaction using Fe2+ ions is more efficient in decomposition than the Fenton-like reaction with existing Fe3+ ions. Higher concentrations of the divalent salt led to a stronger decomposition of the analytes investigated. Cl- ions represent traps of hydroxyl radicals. I demonstrated their interference effect by adding different concentrations of KCl salt to the experimental mixture for the Fenton reaction. In the case of caffeine decomposition, the addition of anions had no effect on the extent of degradation, whereas the opposite effect occurred with theophylline. I tried to determine the order of the reaction, but it turned out that the reaction is of a non-integer order. The decomposition reaction is most effective in the acidic range at pH = 3, and during decomposition I could not detect any compounds that would absorb light with wavelengths up to 230 nm, where acetic acid cut off. No decomposition products could be determined in the mass spectra of the final solution either. Finally I determined the conditions for a 100% decomposition. These are: pH = 3, (H2O2) = 100 μmol/L in c(Fe2+) = 100 μmol/L
Secondary keywords: theophylline;caffeine;Fenton's reagent;liquid chromatography;mass spectroscopy;
Type (COBISS): Master's thesis/paper
Study programme: 1000375
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, smer Kemija
Pages: 43 str.
ID: 12349067