diplomsko delo univerzitetnega študijskega programa I. stopnje
Kristina Preskar (Author), Darinka Brodnjak-Vončina (Mentor), Maša Islamčević Razboršek (Co-mentor)

Abstract

Razvili smo GC–MS metodo za ločevanje in določanje monosaharida glukoze in sladkornega alkohola manitola v različnih ekstraktih listov oljke (Olea europaea L.). Opisana metoda ob predhodni tvorbi oksimov in trimetilsililiranih (TMS) derivatov omogoča dobro ločevanje in kvantitativno določanje termično dovolj obstojnih in hlapnih t.i. oksimskih TMS eterskih (o-TMS) derivatov glukoze in TMS derivatov manitola. Za tvorbo oksimskih derivatov smo uporabili kot reagent hidroksilamin hidroklorid raztopljen v piridinu (2-2,5%). Reakcija oksimacije je potekala s segrevanjem 45 min pri temperaturi 70-80 °C. Kot derivatizacijski reagent za reakcijo sililiranja je bil uporabljen N-metil-N-trimetilsilil trifluoroacetamid (MSTFA). Postopek sililiranja se je izvajal na peščeni kopeli pri temperaturi 70-80 °C, 60 min. Spojini smo potrdili z uporabo standardnih spojin in s primerjavo retencijskih časov ter masnih spektrov posnetih pri enakih kromatografskih pogojih. S kvantitativno analizo različnih ekstraktov oljčnih listov, pripravljenih z običajno ekstrakcijo trdno-tekoče z vodo in mešanicami voda/organsko topilo (50:50, vol. %), v različnih razmerjih vzorca s topilom, smo določili vsebnosti obeh spojin. Vsebnost glukoze je bila določena med 39,2 in 169,2 mg g-1 zatehte ekstrakta. Vsebnost manitola pa je bila določena od 92,1 do 222,2 mg g-1 zatehte ekstrakta. Vsebnosti glukoze in manitola so bile določene iz odgovarjajočih umeritvenih krivulj z uporabo fenil β-D-glukopiranozida kot internega standarda (ISTD). Metodo smo validirali, tako da smo določili linearnost, natančnost kot ponovljivost in obnovljivost, heteroscedastičnost, mejo zaznavnosti (LOD) in mejo določljivosti (LOQ). Ugotovili smo, da je metoda linearna v koncentracijskem območju od 5 do 200 mg L-1, s korelacijskimi koeficienti (r2) večjimi od 0,993. Metoda je natančna in ponovljiva z relativnimi standardnimi odmiki (RSD) pod 15%. Za glukozo smo določili mejo zaznavnosti (LOD) 0,35 mg L-1 in za manitol 0,25 mg L-1. Meja določljivosti (LOQ) je bila za obe spojini 1 mg L-1.

Keywords

validacija;biomasa;plinska kromatografija;masna spektrometrija;glukoza;manitol;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher: [K. Preskar]
UDC: 543.51:[543:662.6](043.2)
COBISS: 17453590 Link will open in a new window
Views: 2616
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Other data

Secondary language: English
Secondary title: METHOD VALIDATION MONOSACCHARIDES DETERMINATION IN THE BIOMASS HIDROLYZATE USING GAS CHROMATOGRAPHY AND MASS SPECTROMETRY
Secondary abstract: A GC–MS method for the separation and determination of the monosaccharide glucose and for the sugar alcohol mannitol in different olive leaves (Olea europaea L.) extracts was developed. The described method by preliminary formation of the oxime and trimethylsilylated (TMS) derivatives provides a good separation and quantitative determination of thermally stable and volatile so called oxime TMS (o-TMS) derivatives of glucose and TMS derivates of mannitol. For the formation of oxime derivatives hydroxylamine hydrochloride dissolved in pyridine (2-2.5%) was used as a reagent. Oximation reaction was carried out by heating 45 minutes at a temperature of 70-80 °C. For silylation reaction N-methyl-N-trimethylsilyl trifluoroacetamide (MSTFA) was used as a derivatisation reagent. Silylation process was performed in a sand bath at a temperature of 70-80 ° C in 60 min. The compounds were confirmed by the use of standard compounds, and by a comparison of retention times and mass spectra´s. By the quantitative analysis of different olive leaves extracts, the amounts of glucose and mannitol were determined. Amounts of glucose ranged between 39.2 and 169.2 mg g-1 dry weight of extract while the amounts of mannitol varied from 92.1 to 222.2 mg g-1 dry weight of extract. The levels of glucose and mannitol were determined from the corresponding calibration curves using the phenyl β-D-glucopyranoside as an internal standard (ISTD). The method was validated, so the linearity, accuracy as repeatability, heteroscedasticity, limit of detection (LOD) and limit of quantitation (LOQ) were determined. It was found that the method is linear in the concentration range from 5 to 200 mg L-1, with the correlation coefficients (r2) greater than 0.993. The method is accurate and reproducible with a relative standard deviation (RSD) below 15%. The LOD`s for glucose and mannitol were 0.35 mg L-1 and 0.25 mg L-1, respectively. The LOQ`s for both compounds were 1 mg L-1.
Secondary keywords: validation;biomass;gas chromatography;mas spectrometry;glucose;mannitol;
URN: URN:SI:UM:
Type (COBISS): Bachelor thesis/paper
Thesis comment: Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages: IX, 36 str.
ID: 8727357