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Determination of the fatty acids composition in selected hardened fats
JANEŠÍKOVÁ, Kristina
The aim of this work is to get oneself acquainted with the method of spectrum evaluation of fatty acids in hardened fats by means of gas chromatography and mass spectrometry. The theoretical part deals with information concerning the types of lipids, their compositions, properties of fatty acids especially in oils and hardened cooking fats and with basic information regarding the methods of oil hardening. This part is concentrated on the evaluation method of fatty acids by means of gas chromatography with the use of gualitative using the mass spectrometry. The fatty acids were evaluated in some commercially available fats (Albert, Ceres Soft, Iva, Lando, Lira, Omega, Varoma). Palmitic acid (hexadecane acid) was represented in the highest proportion in all fats, it was 36-45.5%, frequently represented was also oleic acid (cis-octadec-9-ane) with its 32.2-39%. The last of the more frequently represented acids is the linoleic acid (cis, cis-octadeca-9.12-diene) with its 7.7% to 10.5%. A lower amount of the linoleic acid is contained in the Albert fat, where it is represented with 4.5% only. Interesting is the content of acids being typical for milk fat of ruminants, it includes the caprylic acid (octane), capric acid (decane) and lauric acid (dodecane) and the content of trans-acids. The hardened Albert fat has the highest content of trans-acids, they occupy 23.4% of the product. On the base of this result it can be deducted that this product has probably a lower quality than other ones. In comparison with other fats, the content of acid typical for milk fakt is higher in the Lando and Iva fats. This results indicate the milk fat was probably added in these products during the production. In the time period of one year no considerable changes in the composition of selected hardened fats were registered, however, from the long termed point-of-view, there is an evident marked alternation in the composition of the Ceres Soft and Omega hardened fats being accompanied with a basic decrease of trans-acids.
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Analysis of organic acids by a novel procedure of extractive derivatization in human plasma and serum by GC/MS
JAHODOVÁ, Lucie
The theme of the bachelor{\crq}s thesis was ``The Analysis of Organic Acids by New Extractive Derivatization Process in Blood Plasma and Serum Using the GC/MS Technique{\crqq}. The objective of the thesis was to develop a method for fast determination of organic acids by a new process of extractive derivatization, to identify and determine organic acids in body fluids, to compare their abundance and to evaluate the possibility of implementation of this method in clinical diagnostics. Body fluids contain hundreds of organic acids, which co-create a clinical picture of a patient{\crq}s health condition. The current research focuses on implementation of methods providing for comprehensive, metabolism-based analysis of these metabolites important from the point of view of diagnostics. Nowadays, an analyst can select from a wide range of methods and several effective analytical and separation techniques for separation, determination and identification of organic acids in complex biological matrices. In the introductory, theoretical part of the bachelor{\crq}s thesis, the knowledge of properties of organic acids and possibilities of their determination are summarized. In the practical part, the method of fast determination of organic acids in body fluids by the GC/MS techniques was developed. By means of this technique, it is possible to analyze large quantities of organic acids in minimum volume of body fluid. Derivatization of a set of several tens of organic acids with ethyl chloroformate in aqueous medium was carried out. The reaction proceeds very fast and at laboratory temperature. The applicability of the developed method was verified through analysis of organic acids in biological samples. In samples of blood serum and plasma, tens of organic acids were identified by means of the above-mentioned method, retention data and EI mass spectra. Experiments performed for the purpose of this thesis proved that derivatization with chloroformates in aqueous medium is a relatively simple, fast and promising method for analysis of organic acids. Follow-up experimental research is necessary to make the methodology applicable in clinical diagnostics and to define advantages and limitations of this new methodological procedure.
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Influence of the laser power and analyte concentration on the results in MALDI-TOF MS of oligosaccharides
Čáslavský, Josef ; Chmelík, Josef
MALDI-TOF MS has been successfully applied for the analysis of a wide range of organic biopolymers including oligosaccharides. We focus our attention to the group of oligosaccharides occuring in beer and in malting and mashing products, which are mainly oligosaccharides containing from 3 to more than 30 glucose units in their molecules. We tried to evaluate various factors influencing the obtained results. We found that the shape of the spectrum depends significantly on the energy of ionising laser pulse and also on the amount of the analyte on the MALDI target. These effects were studied with standard mixtures as well as with real samples.
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