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Analysis of aroma compounds in cosmetics by gas chromatography
Divišová, Radka ; Vítová, Eva (referee) ; Zemanová, Jana (advisor)
This thesis is focused on aroma compounds which are presented in a wide variety of products including perfume, cologne, cosmetics, toiletries, laundry products and detergens. The widespread use and exposure to aroma compounds of aforementioned products could cause a range of the adverse reactions such as contact dermatitis, asthma, eczema and breathing problems. There are a lot of aroma compounds triggering negative allergic reactions but EU regulations limit 26 the most important fragrance allergens. The presence of these substances has to be declared on the product label if a limit of 0,01 % for rinse off and 0,001 % for leave-on products is exceeded. Of these 26 substances, a methodology was elaborated for determination of 12 allergens in a experimental part of this thesis. A method by solid-phase microextraction (SPME) and gas chromatography-flame ionization detection (GC-FID) was applied for fragrance allergens identification, extraction and measurement. The optimal extraction conditions of SPME-GC method were investigated including equilibrium time, extraction time and extraction temperature to increase extraction efficiency. Another important point is the method by SPME-GC-FID was validated and following performance parameters were determined: repeatability, linearity, limit of detection (LOD) limit of quantitation (LOQ). SPME-GC-FID was tested and applied to real samples.
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Methods of evaluation of selected cosmetics
Sládková, Veronika ; Sýsová, Lenka (referee) ; Zemanová, Jana (advisor)
This thesis is devided into two parts. The aim of the first – theoretical – part was to become acquainted with the composition, the importance and the physiology of the skin, with different types and masks in connection with the skin care. The theoretical part deals with the function of particular ingredients contained in selected cosmetics described in research literature and also with methods from which cosmetics can be evaluated. Olive oil is the most described component because it is an important ingredient for all cosmetics this study deals with. The second – experimental – part is focused on evaluating the influence of hydratation of these cosmetics. Hydratation was measured by Courage & Khazaka MPA 5 device, which is based on the capacitance measurement of the condenser. Then, the methodic evaluation of hydratation was made up and the aim of the experimental part was to proove this methodic´s accuracy and to elaborate acquired results.
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Study of fruit ripening and storage
Langová, Jiřina ; Zemanová, Jana (referee) ; Babák, Libor (advisor)
There are many changes in fruit quality during its ripening and storage. The following four apple varieties were studied: Champion, Glostr, Golden Delicious and Idaret. Amount of reducing sugars, total amount of sugars, quantities of acids, refractive solids and loss of starch were monitored. The changes of parameters, the differences between the varieties and differences in storage were compared. Parameters were monitored from mid-August 2008, when the apples ripened. After the harvest, apples were stored in a cool box at 2 - 3 ° C and at room temperature 20 - 23 ° C. Apples stored in the cool box were analyzed till the end of March 2009, and apples stored at room temperature until the beginning of January 2009. Total quantity of sugars in all varieties increases before harvest, while it decreases after picking the apples. The quantity of reducing sugars in apples rises gradually and after their picking it falls significantly in apples stored at 20 - 23 ° C. In apples stored in the cool box it continues rising until the end of November, and then it also decreases. Losses of starch are considerable and they are accelerated after the harvest. The quantity of acids also decreases throughout and amounts of refractive solids increases. For all varieties there are significant changes in storage at 20 - 23 ° C. Temperature, therefore, significantly affects processing of sugars and acids in fruit respiration.
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Determination of alergenic and potential alergenic metals in cosmetics
Krakovková, Lenka ; Zemanová, Jana (referee) ; Diviš, Pavel (advisor)
The aim of the diploma thesis was to provide an overview of the prevalence of allergenic and potentially allergenic metals in eye shadows. The diploma thesis gives an overview of the legislation on cosmetics and description of the types of allergenic reactions caused by allergenic and potential allergenic metals in eye shadows. Listed below are the preparation methods of the samples for analysis and the list of the methods by which can the selected metals be analyzed. The experimental part of the diploma thesis deals with an analysis of selected allergenic and potentially allergenic metals in eye shadows. In the experimental part of diploma thesis method of sample preparation for analysis of eye shadows and a method of analysis of sample of eye shadows by ICP-MS have been optimized. Monitored analytes were selected metals. Altogether 6 samples of eye shadows from different manufacturers were chosen. Measured results have been statistically processed, confronted with the applicable legislation and assessed in terms of possible allergic reactions.
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Determination of caseins by capillary electrophoresis
Mičíková, Ivana ; Zemanová, Jana (referee) ; Vespalcová, Milena (advisor)
The diploma thesis, Determination of the caseins by the capillary electrophoresis, is dealing with a creating of the analytical method for a determination of the caseins in cow‘s milk. The capillary electrophoresis was used as a separative method. The developed procedure was optimalized and verified on standards of the caseins and the real samples. The theoretical part gives an information about the compound of cow's milk, caseins, their usage in the food industry and the non-food technologies. There are mentioned some further nutritional factors, whose application in the cattle nutrition can affect the milk composition. The experimental part describes the procedure of the caseins isolation from milk, the used separative system and the determination of the caseins in the lyophilisated samples of milk. The separation was performed in two untreated fused-silica capillaries. Both of them had the same internal diameter: 50 m. The total length of the first capillary was 96 cm (71 cm of effective length) and of the second used capillary 125 cm (effective length 100 cm) The phosphate buffer (10 mM, pH 2,5) served as a basic electrolyte. The diploma thesis has arisen on the basis of the cooperation of the Institute of Food Science and Biotechnology, the Faculty of Chemistry, Brno University of Technology and the Research Institute for Cattle Breeding, Ltd., Department of Animal Nutrition Physiology in Pohořelice.
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Study of selected vegetable oils from nuts
Lovásová, Kristína ; Kovalčík, Adriána (referee) ; Zemanová, Jana (advisor)
The bachelor´s thesis deals with the characterization of the selected nut oils. The theoretical part concentrates on the topic of vegetable oils, their composition and properties. It also focuses on the nuts, the specification of the selected nut oils and their use in different industries. It includes an overview of analytical methods suitable for assessing the quality of oils. The experimental part compares the results of the oil characterization using the selected methods. Based on the results, the differences between the samples were evaluated. The properties of the oils were determined on the basis of fat characteristics. These were subsequently specified by the determination of fatty acid composition. Fatty acids were determined using gas chromatography with a flame-ionization detector after conversion to methyl esters by acid esterification with boron trifluoride. The determination of volatile compounds was performed through solid-phase microextraction with gas chromatography separation and mass spectrometry detection. According to the fat characteristics, in particular the peroxide value, it was found that both oils were partially oxidatively degraded, even though they were stored in the refrigerator (4 °C). A total of 13 saturated, 7 monounsaturated and 4 polyunsaturated fatty acids were detected. The total content of fatty acids varied, the higher content was detected in the walnut oil. Significant differences occurred in the composition of unsaturated fatty acids; the hazelnut oil had a higher content of monounsaturated oleic acid, the walnut oil had a high content of polyunsaturated linoleic and -linolenic acids. A total of 29 volatile compounds were identified, the number and content of volatile compounds in samples differed. 20 volatile compounds were identified in the walnut oil, and 19 compounds in the hazelnut oil. The higher content was in the hazelnut oil, the quantitatively most important group were aldehydes in both oils.
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The possibilities of the assessment of volatile fatty acids
Svítilová, Lenka ; Zemanová, Jana (referee) ; Vítová, Eva (advisor)
This bachelor's thesis deals with common characteristics of fatty acids by description of the structure and terminology of volatile fatty acids, by description of the characteristics and areas of their occurrence. Then possibilities of identification of volatile fatty acids are charted, to which gas chromatography, gas chromatography-mass spectrometry, high performance liquid chromatography, solid phase microextraction, spectrophotometry and isotachophoresis belong. Gas chromatography is the most frequently used method of the detection of volatile fatty acids. During the assessment these substances are mostly converted to methylesters because of their chemical characteristics.
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Silver based raw materials for cosmetic purposes
Čaková, Adriana ; Ďubašáková, Mária (referee) ; Zemanová, Jana (advisor)
The purpose of this bachelor’s thesis was a research about silver based cosmetic products and determination of antimicrobial activity on certain species of microorganisms by chosen silver based cosmetic products. Theoretical part is focused on the problematics of silver based cosmetic products, on their main purpose, physically chemical characteristics and toxicological profile. In the theoretical part is also mentioned problematics of legislative, mainly the safety and real effectivity of tested cosmetic products. Experimental part was focused on determination of antimicrobial activity of chosen silver based cosmetic products. Two silver based cosmetic product were used to determined antimicrobial activity on selected microorganisms Bacillus subtilis, Bacillus cereus, Micrococcus luteus, Kocuria rosea, Serratia marcescens a Candida vini. From result it is apparent, that both of used Cosmetic product showed antimicrobial activity, but not on every used microorganism.
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Optimization of plasmid DNA isolation by magnetic particles
Chlopková, Barbora ; Zemanová, Jana (referee) ; Brázda, Václav (advisor)
The theoretical part summarizes information on the isolation and purification of plasmid DNA and nucleic acids as. Plasmid DNA is often used in gene engineering as a vector for the transfer of a particular gene. Its insulation and transportation in sufficient quality is crucial for other processes associated with it. Isolation and survival of pDNA using magnetic carriers of different concentrations of PEG 8000 in combination with 1M NaCl was investigated in experimental parts. Furthermore, the isolation of pDNA using commercial kits was examined.
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Influence of elevated carbon dioxide concentration at Rubisco activity and its content in sunny and shaded needles of Norway spruce
Šibravová, Lenka ; Zemanová, Jana (referee) ; Hrstka, Miroslav (advisor)
Diploma thesis’s aim was to determine Rubisco activity and its content in sunny and shaded needles of Norway spruce (Picea abies [L.] Karst.) and confirm or refuse acclimation on Rubisco enzyme level. Samples were taken on the Experimental ecology station Czech Academy of Sciences at Bílý Kříž (Beskydy Mountains) where needles were cultivated in two cultivation spheres with different concetrations CO2. One cultivation sphere contains atmosphere with ambient (A) concentration CO2 (350 mol CO2 mol-1) and the other contains atmosphere with elevated (E) concentration CO2 (700 mol CO2 mol-1). Rubisco activities were determinated spectrophotometric, Rubisco content was determined by SDS-PAGE method. Samples were taken in the modele of June and in the end of September. Elevated concetration CO2 did not have significant influence on Rubisco activity. Whereas different exposition had significant influence on Rubisco activity in June, when was found lower Rubisco activity in shaded needles than in sunny needles. In September were not find significant differences in Rubisco activity beetwen sunny and shaded needles. We did not find statistically significant differences in Rubisco content between A and E needles in June. Incontrary, we found about 34 % lower Rubisco content in E needles than in A needles, which confirms acclimation on Rubisco enzyme level. In September Rubisco content was several time higher than in June, which evidences the long term building photosynthetic apparatus in coniferous trees.
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