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The assesment of chloramphenicol residues in biological material, water and feed by GC/MS
Lukačková, Dagmar ; Šalplachta, Jan (referee) ; Rejtharová, Martina (advisor)
This diploma thesis addresses the presence and determination of chloramphenicol residues in biological materials. The theoretical part presents the literature retrieval containing information about veterinary medicaments with the banned use in food producing animals and also the sum of the legislative requirements concerning the presence of these substances in foodproducts and raw food materials of animal origin. The comparison was carried out between the existing analytical methods used for the determination of chloramphenicol residues in different biological materials, which are altogether based on the solid phase extraction for the extract cleaning and the new procedures for sample preparations using columns where the sorbent performs on the molecularly imprinted polymers principle.
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Multirezidual analysis of selected pesticides in barley
Ehrenbergerová, Martina ; Duroňová, Kateřina (referee) ; Mikulíková, Renata (advisor)
Barley is one of the economically important crops. Its production is primarilly used as fodder barley and also in brewery and food industry. Particularly the part of its production intended for malt production must be of high quality. There are some important factors which can influence the quality of the crops, such as harmful organisms – diseases, pests and weed. In order to regulate the occurence of harmful organisms, agricultural measures are taken in the integrated protection system and resistant variants and pesticides are used. The higher the demand on the production quality, the bigger is the volume and the spectrum of pesticides used. The increasing extent of pesticide use also poses a risk for internal production quality and the environment. This fact makes it necessary to monitor unfavourable influences, including the contents of the pesticide residues in barley. This work studies the possibility of multiresidual determination of some selected pesticides in malting barley.
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The application of pollen as bioindicator of the environmental state
Marečková, Kateřina ; Vávrová, Milada (referee) ; Čáslavský, Josef (advisor)
Pesticides and their excessive use lead to environmental pollution. Violation of the guidelines for their use disposal of empty containers could lead to contamination of water, soil and poisoning of animals and beneficial insects. Honey bee is useful creature on our planet. Good farming depends entirely on the pollination, but whole vegetal kingdom couldn’t exist it form known and used by mankind. Therefore, rules that protect these useful creatures against inadequate use of pesticides have been developed. This study focuses on the evaluation of the possibility to use bee products as bioindicators of the state of environment. Five active substances which are components of pesticides used in the treatment of agricultural field around Tasovice village were analysed in the pollen and honey. For sample preparation QuEChERS and SPE methods were used, gas chromatography with to mass spectrometric detection was employed as final analytical technique.
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Extraction of selected elderberry flavonoids for food industry purposes
Grulichová, Hana ; Hrstka, Miroslav (referee) ; Vespalcová, Milena (advisor)
Amount of rutin and quercetin in bark and leaves from different type of Sambucus nigra was determined in this diploma thesis. Records of amounts were compared with amounts in significant sources of these flavonoids. Matters from raw matrix were obtained with pressurized solvent extraction (PSE) and pressurized hot water extraction (PHWE). There was use temperature 120°C, pressure 150 bar, three times 5-min cycles for PSE. There were used 80°C, 150 bar, three 5-min cycles for rutin extracted with PHWE and the same condition were used for extraction of quercetin only the temperature was changed to 100 °C. Analysis of rutin and quercetin were carry out high performance liquid chromatography (HPLC) with diode array detection (DAD), where was used SUPELCOSILTM LC 8DB column (5µm; 250 x 4.6 mm). Methanol: water: formic acid (36: 61.5: 2.5, pH 2.17 2.28) was used like a mobile phase. The flow of the mobile phase was set up 0.7 ml/min. Size of sample was 10 µl. The most amount of rutin was determined in the leaves of wild kind of Sambucus nigra with methanol extraction and hot water too. Extraction with PHWE was more effectively. There were determined 5.58 mg of rutin in one gram of sample from wild Sambucus nigra. There were determined the smallest amount of rutin in Sambucus nigra Körsör. There was found only 0.13 mg/g with extraction PHWE. The quercetin wasn’t determined in any Sambucus nigra leaves. There were found both of the flavonoids (rutin and quercetin) in the branch of Sambucus nigra. The rutin was determined in the small amount in wild kind but it was found in the important amount in Sambucus nigra cultivar. Whereas the quercetin was found in higher concentration than rutin when was finding the ideal conditions for extraction of branch. The quercetin was chosen like more important in light of amount. In the end the quercetin wasn’t detected in any Sambucus nigra cultivars. The most amount of quercetin was determined in wild sambucus nigra, 0.24 mg/g. The most amount of rutin was found in Sambucus nigra Albida, 2.33 mg/g.
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Preconcentration of Trace Analytes on Modified Sorbents and their Determination on Waters
Holubová, Zuzana ; Čelechovská, Olga (referee) ; Holoubek,, Ivan (referee) ; Otruba,, Vítězslav (referee) ; Sommer, Lumír (advisor)
The work has been focused on the preconcentration techniques for determination of 9Be, 51V, 59Co, 60Ni, 89Y, 111Cd, 208Pb, 232Th and 238U on the modified sorbents, all measurements were performed on ICP-MS. The instrument setup was optimized. The solution of internal standard (200 µg•l-1) was used during all measurements. The internal standard were chosen as follows: 6Li for 9Be, 45Sc (51V), 72Ge (59Co, 60Ni, 89Y), 103Rh (111Cd), 209Bi (206Pb, 207Pb, 208Pb, 232Th and 238U). Another parameters such as influence of mineral acids (HCl, HNO3), surfactant (Septonex®, Zephyramin, Ajatin, Brij 35 and Sodium dodecyl sulphate) and organic reagents (Ammonium pyrrolidinedithiocarbamate, 8-Hydroxyquinoline-5-sulphonic acid, 1,2-Dihydroxyanthraquinone-3-sulphonic acid and 4-(2-Pyridylazo)resorcinol) and the effect of some matrix components on intensity of instrument signal determination was investigated. For preconcentration polar Silicagel and modified nonpolar Silicagels (Silicagel-C18, C8 nad Phenyl) were used. Another experimantal part was dedicated to preconcentration on nonpolar Amberlite XAD-16 and Strata SDB-L and intermediately polar sorbent Amberlite XAD-7. Recoveries of sorption process were observed in the presence of all testing types of surfactants in certified concentration 5•10-4 mol•l-1. Surfactants were always applied in the conditioning step. The suitable combinations of surfactant and organic reagent were tested for increasing of recoveries of analytes. Testing organic reagents were added in five times mass excess againts concentration of analytes, the concentration of the organic reagents was 900 µg•l-1. The organic reagent was always added to the solution for preconcentration before this solution was led on the sorbent. The composition and a necessary volume of elution mixture for quantitative elution were tested, too. Only one sorbent was chosen from each group of sorbents with similar properties. The chosen sorbent showed the best recoveries in majority of target analytes. The highest recoveries from silica-group was reached for Silicagel-C18, from nonpolar Amberlite was chosen Strata SDB-L and intermediately polar Amberlite XAD-7. The influence of some matrix components (anionts and cations) on recoveries of analytes was investigated for chosen sorbent. The optimized process was applied on real samples of nature water and industry water. In experimental part all analytes are marked as specific izotopes, which were measured by ICP-MS. Of course, all izotopes of analytes undergo preconcentration techniques.
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The possibilities of assessment of free fatty acids
Hornáková, Miroslava ; Vespalcová, Milena (referee) ; Vítová, Eva (advisor)
This thesis deals with the determination of free fatty acids in natural and processed cheese. In the theoretical part the possibilities of extraction, fractionation and determination of lipid fractions, characterization of fatty acids and various methods of their determination are described, including the determination of free fatty acids. In the experimental part the selected method for determination of free fatty acids was optimized and partly validated; this method was then applied to samples of processed cheese analogues and natural Gouda type cheese. For extraction of lipids from the sample the method according to ČSN 0107 was selected, solid phase extraction (SPE) was used for separation of free fatty acids. The method according to ČSN EN ISO 5509, using methanol solution of potassium hydroxide, was applied for esterification, fatty acids methyl esters were determined by gas chromatography with FID detection.
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Preconcentration Techniques for Determination of Uranium Using the Modified Sorbents.
Moos, Martin ; Řehůřková, Irena (referee) ; Kanický, Viktor (referee) ; Kráčmar, Stanislav (referee) ; Sommer, Lumír (advisor)
The work has been focused on the preconcentration techniques for determination of uranium on the modified sorbent, with the final use of ICP-OES and ICP-MS. First ICP-OES at a wavelength of 385.958 nm was used for determination of uranium. Parameters were optimized and the effect of mineral acids (HCl, HNO3), tensides (Septonex, Ajatin) and organic reagents like (4-(2-pyridylazo)resorcinol, ammonium pyrrolidinedithiocarbamate, 8-hydroxyquinoline-5-sulphonic acid and 1,2-dihydroxyanthraquinone-3-sulphonic acid) was observed. For ICP-MS an isotope 238U was chosen. As an internal standard 209Bi (200 ?g•l-1) was used. Modified silica gel was used (Silicagel tethered with C18, C8 alkyls and phenyl) and two types of Amberlite XAD 4 and XAD 16 for the preconcentration of uranium (VI). Commercially produced Amberlite was modified as follows: Drying at 100 °C (24 hours), milled, minced sorbent was selected and fractionated to particles size ranging from 0.32 to 0.63 ?m and finally activated in methanol. The deionised water and Septonex (5•10-3 mol•l-1) at pH 8 were used for Amberlite conditioning. The optimal sorption of uranium (VI) proceeded at pH 8 in the presence of 4-(2-pyridylazo)resorcinol or ammonium pyrrolidinedithiocarbamate with Amberlite XAD-16 moreover with 1,2-dihydroxyanthraquinone-3-sulphonic acid. All organic reagents have mass concentration five time larger than uranium . For the elution of uranium the mixture of 1 mol•l-1 HNO3 with acetone (ratio of 1:1) was used. Acetone was evaporated and the final analysis performed using ICP-OES. The preconcentration of uranium (VI) using Silicagel-C18 conditioning was performed with ethanol, deionised water and Zephyraminu (5•10-4 mol•l-1) at pH 8. For the Silica-C8 and Silicagel-Phenyl the same conditioning procedure without zephyramin was used. Silica-C18 had the highest sorption efficiency with 1,2-dihydroxyanthraquinone-3-sulphonic acid, Silicagel-C8 with ammonium pyrrolidinedithiocarbamate and Silicagel-Phenyl with 8-hydroxyquinoline-5-sulfonic acid, all organic reagents have mass concentration five time larger than uranium concentration. As an optimal elution mixture acetone and ethanol (ratio of 1:1) in the presence of 1 mol•l-1 HCl was evaluated. Acetone and ethanol was evaporated and the final analysis was performed using ICP-MS. Silicagel-C18 was evaluate as the most effective in the presence of zephyramin and 1,2-dihydroxyanthraquinone-3-sulphonic acid. Sorption was also tested in the presence of 20 ?g•l-1 microelements (Be, V, Co, Ni, Y, Pb, Th, Cd) and in the presence of a defined concentrations of K, Na, Ca, Mg, Al and Fe. Direct analysis of uranium was carried out on samples of water from the river Ploucnice and Turonian aquifers containing uranium, 3,5 and 19,3 ?g•l-1. Different type of water required preconcentration of uranium (VI) on Silica-C18 in the presence of 1,2-dihydroxyanthraquinone-3-sulphonic acid and zephyramin. The analysis results gave statistically satisfactory results, which were confirmed using standard addition of 20 ?g•l-1.
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Monitoring of organic acid content in alcoholic drinks
Ostrihoňová, Katarína ; Běláková, Sylvie (referee) ; Benešová, Karolína (advisor)
The aim of the thesis is determination and optimization of organic acids in beers using the methods of capillary isotachophoresis (CITP) and high performance liquid chromatography with diode array detection (HPLC/UV). Beer is a complicated matrix therefore the samples need pretreatment using solid phase extraction (SPE). The diploma thesis discusses the optimization of the analytical methods (HPLC/UV and CITP) and optimization of SPE. In the theoretical part, history, characterization and technology of beer production are presented. Further, characteristics of organic acids and methods for organic acid determination are also discussed. The experimental part deals with the preparation of solutions, tested samples, calibration samples. Parameters and procedures of analytical methods (HPLC/UV and CITP) and pretreatment using the solid phase extraction are also described in the experimental part. All results are summarized and compared with the current literature in discussion and conclusion. Eleven beer samples from the retail stores were analyzed. In all samples, six organic acids (lactic, oxalic, succinic, acetic, citric, benzoic) were determined by CITP and five organic acids (lactic, oxalic, succinic, acetic, citric) by HPLC/UV were determined. Results of this study give an overview of the organic acid contents in beer samples.
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Study of contamination of river sediments with platinum metals
Novotný, Matěj ; Řezáčová, Veronika (referee) ; Komendová, Renata (advisor)
This work deals with the characteristics of platinum metals and problems related to their toxicity and mobility in the environment, especially in the aquatic environment. These metals are released into the environment due to the use of automotive catalysts. Their function is based on the catalytic properties of platinum metals. Because of the high temperatures, these metals can be oxidized in the catalyst and subsequently emitted together with the combustion products into the surrounding atmosphere. The aim of the thesis is to measure real samples of river sediments of the river Svratka on the territory of the city of Brno and to find the possibility of contamination of the aquatic environment with these metals.
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