diplomsko delo visokošolskega študijskega programa
Tina Pintar (Author), Darinka Brodnjak-Vončina (Mentor), Maša Islamčević Razboršek (Co-mentor)

Abstract

Olivna biomasa je obnovljiva surovina za proizvodnjo kemikalij in organskih spojin, goriv ter energije. Rastline oljk vsebujejo v različnih tkivih različne ogljikove hidrate kot so glukoza, manitol, saharoza in rafinoza. Znanstveni prispevki s področja analize sladkorjev v rastlinah obravnavajo različne metode, ki omogočajo njihovo izolacijo, čiščenje, medsebojno ločevanje, identifikacijo in kvantitativno določanje. V okviru diplomske naloge smo določili vsebnost monosaharida glukoze in sladkornega alkohola manitola v različnih ekstraktih oljčnih listov (Olea europaea L.), pripravljenih s subkritično vodno ekstrakcijo, ob uporabi različnih temperatur (80 °C, 120 °C in 180 °C), različnih tlakov (30 bar, 80 bar, 100 bar in 150 bar) in različnega časa ekstrakcije (5 min, 10 min, 30 min, 60 min in 90 min). Vzorce smo analizirali s plinsko kromatografijo in masno spektrometrijo (GC-MS). Preiskovane spojine smo pred analizo pretvorili najprej v oksimske (o-) in nato v trimetilsililirane (TMS) derivate, ki so bili termično dovolj obstojni in hlapni za analizo z GC. Za tvorbo oksimskih derivatov smo uporabili kot reagent hidroksilamin hidroklorid raztopljen v piridinu (2-2,5%), za reakcijo sililiranja pa je bil kot derivatizacijski reagent uporabljen N-metil-N-trimetilsilil trifluoroacetamid (MSTFA). Spojine smo potrdili z uporabo standardnih spojin, s primerjavo retencijskih časov in masnih spektrov. Spojine smo v rastlinskih ekstraktih kvantitativno določili iz umeritvenih krivulj ob uporabi fenil β-D-glukopiranozida kot internega standarda (ISTD). GC-MS je omogočila sočasno ločevanje in selektivno identifikacijo strukturno podobnih ogljikovih hidratov kot sta glukoza in manitol ter različnih stereoizomerov kot so α- in β-TMS-glukopiranoza ter sin- in anti-oksim-TMS-glukoza. Pridobljene rezultate smo statistično ovrednotili in dokazali, da je metoda natančna, linearna in ponovljiva. Ocenili smo tudi merilno negotovost pri določanju koncentracije glukoze in manitola ter prav tako ovrednotili vse možne vire merilne negotovosti, ki nastajajo pri izvajanju analiznega postopka. Iz rezultatov smo ugotovili, da je največ glukoze (2,576 g/L) in manitola (4,031 g/L) v vzorcu ekstrakta oljčnih listov, ekstrahiranem s subkritično vodo pri 80 °C ter 90 min. Najnižjo vsebnost glukoze (0,489 g/L) in manitola (1,321 g/L) pa smo določili v vzorcu, ekstrahiranem s subkritično vodo pri 180°C ter 90 min.

Keywords

lesna biomasa;oljčni listi;glukoza;manitol;plinska kromatografija;masna spektrometrija;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher: [T. Pintar]
UDC: 543.635.22:543.51/.54(043.2)
COBISS: 18008854 Link will open in a new window
Views: 1767
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Other data

Secondary language: English
Secondary title: MEASUREMENTUNCERTAINTY OF MONOSACCHARIDES CONTENT IN DIFFERENT EXTRACTS FROM OLIVE LEAVES USING GAS CHROMATOGRAPHY AND MASS SPECTROMETRY
Secondary abstract: Olive biomass is a renewable raw material for production of chemicals, different organic compounds, fuels and energy. Olive plants contain in a variety of tissues different carbohydrates, such as glucose, mannitol, sucrose and raffinose. Scientific literature about sugar analysis describes different approaches that enable their isolation, cleaning, separation, identification and determination. In this study, the content of monosaccharide glucose and sugar alcohol mannitol in the various extracts of olive leaves (Olea europaea L.), prepared with subcritical water extraction using different temperatures (80 °C, 120 °C and 180 °C), different pressure levels (30 bar, 80 bar, 100 bar and 150 bar) and different extraction time (5 min, 10 min, 30 min, 60 min, 90 min) were determined. Samples were analyzed by gas chromatography and mass spectrometry (GC-MS). Prior to analysis the investigated compounds were converted firstly into the oxime (o-) and then into the thermally stable and volatile trimethylsilyl (TMS) derivatives. For the formation of oxime derivatives reagent hydroxylamine hydrochloride dissolved in pyridine (2-2,5%) was used and for a silylation N-methyl-N-trimethylsilyl trifluoroacetamide (MSTFA) was used as a derivatization reagent. The compounds were confirmed by using standard compounds and by comparing their retention times and mass spectra's. For the quantitative determination of the compounds in the plant extracts the calibration curve method using phenyl β-D-glucopyranoside as an internal standard (ISTD) was used. GC-MS enabled simultaneous separation and selective identification of structurally similar carbohydrates such as glucose and mannitol and different stereoisomers such as α- and β-TMS-glucopyranose and syn- and anti-oxime-TMS-glucose. Obtained results were statistically evaluated and it was proved that the method is precise, linear and reproducible. The measurement uncertainty of the determined glucose and mannitol concentrations was established and also all possible sources of measurement uncertainty arising from the implementation of the analytical procedure was evaluated. The results confirmed that the highest concentrations of glucose (2,576 g/L) and mannitol (4,031 g/L) were present in a sample where olive leaves were extracted with subcritical water at 80 °C for 90 min and the lowest contents of glucose (0,489 g/L) and mannitol (1,321 g/L) were determined in the sample extracted with subcritical water at 180 °C for 90 min.
Secondary keywords: wood biomass;olive leaves;glucose;mannitol;gas chromatography;mass spectrometry;
URN: URN:SI:UM:
Type (COBISS): Undergraduate thesis
Thesis comment: Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages: XI, 54 f.
ID: 8729817