magistrsko delo
Jerneja Maček (Author), Drago Kočar (Mentor), Iztok Turel (Thesis defence commission member), Matevž Pompe (Thesis defence commission member)

Abstract

Tekočinska kromatografija ultra visoke ločljivosti je novejša različica tekočinske kromatografije. V primerjavi s HPLC sistemi so se izboljšale ločbe, ki so časovno krajše, imajo boljšo ločljivost in občutljivost. UHPLC tehnologija je kolonska kromatografija, zato so bile razvite kolone z delci stacionarne faze, katerih velikost premera ne presega 2 µm, pretoki pa so običajno bistveno pod 1 mL/min. Tlak pred kolono doseže približno 600 bar, kar je predpogoj za prehod mobilne faze skozi kolono. Na sistemu tekočinske kromatografije visoke ločljivosti sem razvila metodo. Preverila sem ponovljivost pri pripravi raztopin, ponovljivost merilnega instrumenta in pripravila umeritveno krivuljo. Z validirano metodo sem nato izvedla eksperiment in preverila stabilnost kinurenske kisline. Kinurenska kislina nastane kot presnovni produkt aminokisline L-triptofana. Reakcija je katalizirana z encimom kinurenin oksoglutrat transminaza. Prisotnost kinurenske kisline so dokazali v različnih delih živih organizmov, v prebavnem traktu, krvi, perifernem živčnem sistemu in možganih. Študije so pokazale, da kinurenska kislina deluje antioksidativno ter protivnetno, saj zavira aminokislinske receptorje. Kinurenska kislina nima vpliva le na organizme, vendar jo najdemo tudi v živilih, kot so krompir, brokoli, številne začimbe ter zelišča. Izjemno veliko koncentracijo kinurenske kisline pa najdemo v medu, posebno v kostanjevem. Na stabilnost kinurenske kisline vplivajo pogoji, katerim je raztopina izpostavljena in medij, ki je raztopini dodan. Raztopina kinurenske kisline je na podlagi izvedenih študij stabilna v kislem in bazičnem mediju ter pri povišani temperaturi. V peroksidnem mediju in izpostavitvi raztopine sončni svetlobi pa kinurenska kislina ni stabilna.

Keywords

kinurenska kislina;stabilnost;UHPLC;validacija analizne metode;magistrska dela;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher: [J. Maček]
UDC: 543.544.5HPLC(043.2)
COBISS: 169808643 Link will open in a new window
Views: 60
Downloads: 8
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Other data

Secondary language: English
Secondary title: Study of the stability of kinurenic acid in aqueous solutions
Secondary abstract: Ultra high-performance liquid chromatography is a newer version of liquid chromatography. Compared to HPLC systems, the separations have improved, which are shorter time, better resolution, and sensitivity. UHPLC technology is a column chromatography, so columns with stationary phase particles of 2 μm in diameter have been developed and flows do not exceed than 1 mL/min. The pre-column pressure reaches around 600 bar, which is a prerequisite for the mobile phase to pass through the column. I developed a method on a high-resolution liquid chromatography system. Checked the reproducibility of the solution, the repeatability of the measuring instrument and prepared the calibration curve. Then I conducted an experiment with a validated method to check the stability of kynurenic acid. Kynurenic acid is formed as a metabolic product of the amino acid L-tryptophan. The reaction is catalyzed by the enzyme kynurenine oxoglutarate transaminase. The presence of kynurenic acid has been demonstrated in various parts of living organisms, in the digestive tract, blood, peripheral nervous system and brain. Studies have shown that kynurenic acid acts antioxidant and anti-inflammatory by blocking amino acid receptors. Kynurenic acid not only affects organisms, but is also found in foods such as potatoes, broccoli, numerous spices, and herbs. An extremely high concentration of kynurenic acid is found in honey, especially in Chestnut´s. The stability of kynurenic acid is affected by the conditions to which the solution is exposed, and the medium added to the solution. The kynurenic acid solution is stable in acidic and alkaline mediums and at elevated temperatures, based on studies carried out. However, in the peroxide medium and exposure of the solution to sunlight, kynurenic acid is not stable.
Secondary keywords: high performance liquid chromatography;kynurenic acid;stability;Vodne raztopine (kemija);Tekočinska kromatografija;Univerzitetna in visokošolska dela;
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: 51 str.
ID: 19913002