Analiza lignoceluloznih materialov z različnimi modifikacijami Klasonove metode

diplomsko delo visokošolskega strokovnega študijskega programa I. stopnje

Dragana Bjelić (Author), Lidija Čuček (Mentor), Maša Islamčević Razboršek (Co-mentor), Marina Tišma (Co-mentor)

Abstract

Osnovna Klasonova metoda je znana že od začetka dvajsetega stoletja in jo je razvil švedski kemik Peter Klason. Klasonova metoda temelji na gravimetričnem merjenju kislinsko netopnega (Klasonovega) lignina. V preteklosti je bilo razvitih tudi veliko modifikacij te metode ter drugih metod. V sklopu diplomskega dela smo primerjali vsebnosti ekstrahiranih snovi, ogljikovih hidratov in kislinsko netopnega lignina, pri čemer smo uporabili različne modifikacije Klasonove metode. Pri analizi smo proučevali različno število stopenj ekstrakcije, različne vrste topil (aceton, etanol, n-heksan, metanol), različne vzorce lignoceluloznega materiala (slame) z različnimi velikostmi delcev ter primerjali vsebnosti Klasonovih komponent zdravih in okuženih rastlin. Glavni namen tega diplomskega dela je ugotoviti, kakšno je odstopanje Klasonovih komponent pri uporabi različnih modifikacij metod ter določiti delež ogljikovih hidratov, predvsem monosaharidov, ki se ekstrahirajo po kislinski hidrolizi. Prav tako je namen izračunati velikost napak, ki se pojavijo med izvedbo eksperimenta. Izvedli smo še osnovno Klasonovo metodo oz. dvostopenjsko ekstrakcijo z acetonom za primerjavo vsebnosti lignina med zdravimi in okuženimi rastlinami. Rezultati kažejo, da iz vidika modifikacij največji delež Klasonovega lignina dobimo pri modifikaciji z enostopenjsko ekstrakcijo s topilom n-heksan in z osnovno Klasonovo metodo. Spremembe ostalih parametrov ne vplivajo tako močno na rezultat kot sama sprememba topila. Narejena je bila še analiza vsebnosti monosaharidov po hidrolizi, pri kateri smo ugotovili velike razlike med paralelkami, kar bi lahko bila posledica nehomogenosti materiala ter premajhnega števila paralelk in ponovitev. Raziskali smo tudi dejavnike in napake, ki povzročajo morebitna odstopanja od realnih vrednosti ter ugotovili, da so ob še tako natančnem delu določene napake neizogibne. Rezultati primerjave vsebnosti Klasonovega lignina med zdravimi in okuženimi rastlinami so pokazali, da do razlik v rezultatih prihaja zaradi nerazgrajene kutikule.

Keywords

lignocelulozni materiali;Klasonova metoda;modifikacija Klasonove metoda;določevanje lignina;določevanje monosahridov;analiza napak;diplomske naloge;

Data

Language:	Slovenian
Year of publishing:	2017
Typology:	2.11 - Undergraduate Thesis
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	[D. Bjelić]
UDC:	664.16:665.947.4(043.2)
COBISS:	21053462
Views:	971
Downloads:	172
Average score:	0 (0 votes)
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Other data

Secondary language:	English
Secondary title:	Analysis of lignocellulosic materials with different modifications of Klason method
Secondary abstract:	Klason's method is known since the beginning of twentieth century and was developed by Swedish chemist Peter Klason. The Klason’s method is based on the gravimetric measurement of the acid insoluble (Klason) lignin. In the past, several methods and modifications of this method have been performed. As a part of diploma thesis fractions of extractives, carbohydrates and acid insoluble lignin have been compared by applying different modifications of Klason’s method. During the analysis, number of stages of extraction, type of solvent (acetone, ethanol, n-hexane and methanol), different samples of lignocellulosic material (straw) with two different sizes of particles, and healthy and infected plants have been compared. The main purpose of this thesis is to determine the deviations of Klason’s components by the use of different modifications of the method, and determine the proportion of carbohydrates dissolved during the hydrolysis. It is also intended to calculate the magnitude of errors that accompany us through the performance of the experiment. A basic Klason’s method of two-stage extraction was performed to compare the lignin content between healthy and infected plants. The results show that in terms of the modifications the highest amount of the Klason’s lignin was obtained with one-step extraction with solvent n-hexane and with the basic Klason’s method. Changes in other parameters do not affect result as much as the change of the solvent. An analysis of the monosaccharide content after hydrolysis was made, where it was found that significant differences between parallels have been obtained, which could be the result of the incomplete homogenization of the material and low number of parallels and repetitions. The problems and errors of the analysis have been investigated and it was found that certain defects are inevitable even with very precise work. The results of comparing the content of Klason's lignin between healthy and infected plants have shown, that the disturbing factor is unstructured cuticle.
Secondary keywords:	lignocellulosic material;Klason's method;modifications of the Klason's method;determination of lignin;determination of monosaccharides;error analysis;
URN:	URN:SI:UM:
Type (COBISS):	Bachelor thesis/paper
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	XII, 62 str.
ID:	10860347