Browsing by Subject "extraction"

Gas chromatography (GC) is one of the most widely used method for analysis of lipids and it is commonly combined to a flame ionization detection (FID), since GC-FID is an excellent combination for quantitative analysis of wide range of lipids. Before GC analysis can be performed, lipids must be extracted from the sample and derivatized. Some common extraction methods include Soxhlet and Soxtec extraction, Folch extraction and extraction with the help of acid hydrolysis. To be able to analyse the extracted fatty acids by GC, they must be in a volatile form. This can be achieved by forming fatty acid derivatives by, for example, methylation. The commissioner wishes to have a way to analyse the fatty acid composition of pork by GC in their laboratory. The aim of the study was to take in use an easy, safe-to-use and simple method for determination of fatty acid composition of pork by gas chromatography, using the instruments and equipment already found from the laboratory. The research had three different parts. First, heptane-isopropanol extraction, Bligh & Dyer extraction and Caviezel extraction were compared. Then the chosen extraction method was validated. Finally, two different pork samples were compared to test the method’s ability to differentiate them. Caviezel extraction was chosen as the best extraction method, and it was validated by parameters repeatability and robustness. The method was able to differentiate samples that had similar, but slightly different fatty acid compositions. However, method still requires some fine tuning since the GC column seemed to be highly sensitive to any disturbances.

Rhazya stricta Decne. is a small evergreen shrub belonging to the Apocynaceae family. The plant grows in South Asia and the Middle East, and in these areas it is used in traditional medicine. All parts of the plant are used in different preparations for a variety of purposes such as infections, bowel diseases, itching and diabetes. R. stricta synthesizes about a hundred different alkaloids, of which only a fraction has been studied closer. Some of the analyzed alkaloids have showed some interesting pharmacological properties such as antibacterial and cytotoxic properties. Because it is often both economically and ecologically unsustainable to cultivate or to collect large amounts of medicinal plants from nature, cell cultures have been developed from plants. The properties and synthesized substances of the cell cultures can be analysed and modified in laboratories. In the experimental part of this work, a system was developed for alkaloid extraction, fractionation and isolation from dried cell material from cultured R. stricta hairy root-cells. The goal was to develop a functioning system that eventually enables identification of the alkaloids synthesized by the cultured cells under given conditions. Alkaloids were extracted from 26 g of dried and ground cell mass. The fractionation of the alkaloids was performed with medium pressure liquid chromatography (MPLC) and the fractions were analyzed by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). The alkaloids were purified by horizontal TLC and preparative HPLC. Ion-pair chromatography was used for analyzing the extract, fractions and purified alkaloids. Five components from two fractions were eventually isolated. One of the components was tentatively identified as vincanine, but further analyzes have to be performed to identify all components reliably. In total, hairy root-cells seem to synthesize approximately 20 alkaloids with variable polarity.

Forest energy harvesting has increased significantly in recent years. The extraction of forest energy is usually done with conventional forwarders. The productivity of extraction work is, however, quite poor due to a low material density, which results in a small load size. The objective of the study was to increase the productivity of forest energy extraction via solutions that increase the load size. The first method that was studied involved widening the load space hydraulically. The other solution was based on compressing the load with hydraulically tiltable stakes. The study was conducted as a development study. The field studies were carried out in the summer and autumn of 2011 on harvesting sites managed by Metsähallitus and Metsäliitto in the Jyväskylä region. The study material comprises a total of 139 loads. There was a significant difference in raw density between the logging residues and stump pieces for the widening and compressing load space solutions. For this reason, it does not make sense to compare the two load space solutions to each other. The analyses were based on the reported load scale tonnes. Both load space alternatives increased the load size by 20-30 per cent depending on the assortment. For logging residues, the increase in efficient hour productivity for extraction was 13 per cent and for stump pieces it was 30 per cent. With the compressing load space, the efficient hour productivity for full trees increased by 17 per cent. For logging residues, the increase was 5 per cent and for stump pieces it was 12 per cent. Compression was not a successful method for stump pieces and even for logging residues the benefits were mainly based on the increased load space. Compressing the load is mainly beneficial when extracting full trees. The project was carried out together with Osuuskunta Metsäliitto (now Metsä Group), Metsä-Multia Oy and Ponsse Oyj. The modelling work was done by Metsäteho Oy. This study shows results of Metsähallitus project “Maastokuljetuksen kehittäminen”. The project is part of the EffFibre (Value through Intensive and Efficient Fibre Supply) research and development programme coordinated by Forestcluster Ltd.

Literature review of the thesis introduces the characteristics of selenium and its importance in human diet. It also gives an overview on different analytical methods used in speciation of selenoamino acids. The aim of this study was to develop a simple and rapid mass spectrometric method which could be used to detect and specify low molecular weight selenoamino acids from different food materials in order to find and quantify probable cancer protective species. Total selenium content was determined by GFAAS from garlic and Brazil nut samples. The selenium concentration in garlic was 0.1 µg/g and 4.4 µg/g in Brazil nuts. Also, the precipitates and supernatants from the sample extractions (hot water, diluted HCl and proteinase K) were analyzed. There were only about 10% of the total selenium in the supernatants (which were further used in analysis). Samples were derivatized by AccQ·Tag reagent (AQC) and analyzed with UHPLC-ESI-MS method. Even though the method was easy and fast to use, it was applicable only for selenoamino acid standards (MeSeCys and SeMet). No results were obtained from the real samples. Therefore, a more sensitive piece of equipment, HPLC-ICP-MS was applied with Hamilton PRP-X100 column and 5 mmol/l ammonium citrate buffer (pH 5.2). Hot water and diluted HCl extracted samples showed no signs of selenium. At last, proteinase K digested Brazil nut sample showed a small peak of SeMet which was identified by retention time matching with the standard and quantified semi quantitatively from standard curve (0,06 µg SeMet /g Brazil nut). This study showed that the sensitivity of the UHPLC-ESI-MS method was not sufficient to detect such low concentrations of selenoamino acids in garlic and Brazil nut samples. However, the AQC derivatization together with UHPLC-ESI-MS offers a fast, linear and repeatable method for future amino acid analysis.

Viisaudenhampaat aiheuttavat monenlaisia ongelmia ja siksi niiden poisto koskettaa lähes jokaista suomalaista. Tutkimuksen tarkoituksena on selvittää viisaudenhampaiden poistoihin johtavien diagnoosien yleisyyttä, poistotapaa, potilaan ikää poistohetkellä ja sukupuolten välisiä eroja. Tutkimuksen aineistona oli Helsingin kaupungin terveyskeskuksen potilastietojärjestelmästä Efficasta aikaväliltä 1.1.2013 - 8.12.2014 viisaudenhampaiden poistoihin liittyvät tiedot: hampaan numero Dd.18, 28, 38, 48, ICD-10 tautiluokituksen mukainen poistodiagnoosi, EBA-alkuinen toimenpidekoodi, potilaan ikä poistohetkellä ja sukupuoli. Tutkimusaineisto koostui 8436 poistetusta viisaudenhampaasta (51 % miesten hampaita, ikähajonta 10-99 vuotta). Aineisto analysoitiin Excelissä. Ryhmien välisten erojen tilastollista merkitsevyyttä testattiin Khi toiseen -testillä. Yleisimmät poistodiagnoosit jakautuivat seuraaviin luokkiin: K05 Hampaiden kiinnityskudosten sairaudet (23 %), K04 Hammasytimen ja hampaan juuren kärkeä ympäröivien kudosten sairaudet (20 %) sekä K02 Hammaskaries (18 %). Leikkaamalla poistettiin vain 27 % kaikista viisaudenhampaista, joista 81 % oli alaleuan hampaita ja joiden yleisimpänä poistodiagnoosina oli pitkäaikainen perikoroniitti (16 %). Yleisin poistoikä oli 20-29 vuotta (34 %). Miehiltä poistettiin viisaudenhampaita keskimäärin 38 vuoden ikäisenä ja naisilta 35,3-vuotiaina. Johtopäätöksenä todetaan, että viisaudenhampaita poistetaan terveyskeskuksessa yleisten biofilmisairauksien takia ja suurin osa tehdään tavanomaisina poistoina.