The aim of this diploma thesis was to develop a miniaturized extraction method for a fast screening of non-volatile nitroso compounds using gas chromatography with a nitroso specific chemiluminescence detection. According to a final methodology, the samples were prepared by extraction of grinded malt using a mixture of pyridine and acetonitrile in ratio 60:40 (v/v). To enhance volatility of the determined analytes, the two-step derivatization using hexamethyldisalazane and N,O-bis(trimethyl)-trifluoroacetamide was used. The total volume of the sample was 200 l and the preparation time after optimization was in total 80 min. The extraction method was connected to a classification method, which can divide chromatographic peaks into the groups of N-nitroso and C-nitroso compounds, and interfering substances. After application of the methods mentioned above to real malt samples, the specific chromatographic peaks of C-nitroso and N-nitroso compounds were selected. Description of their properties and structure suggestion will be a subject of the following study. Keywords Nitroso compounds, malt, extraction, derivatization, gas chromatography, chemiluminescence detector

Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department: Pharmaceutical Chemistry and Drug Control Candidate: Zbyněk Mrůzek Supervisor: prof. RNDr. Jiří Klimeš. CSc Consultant thesis: Ing. Pavel Blatný. Ph.D. Title of thesis: Determination of related substances in the dosage forms based on cyclosporine by HPLC with nitrogen specific chemiluminescence detection. Development of an HPLC method with chemiluminescent detection specific for nitrogen for related substances determination in cyclosporine final dosage forms is described in this work. The method is capable to determine cyclosporine impurities originated from cyclosporine substance and relevant degradation products except isocyclosporines. The method utilizes the stationary phase Zorbax SB-C18, particle size 1.8 µm, 150x2.1 mm and gradient elution at flow rate 0.15 ml.min-1 at column temperature 100řC. Mobile phases are Acetone: TBME: water: TFA (30: 5.5: 64.5: 0.01) and Acetone: TBME: water: TFA (49: 5.5: 45.5: 0.01). The work includes the verification of method validability in terms of specificity, linearity, limit of quantittion, accuracy, precision and robustness. The method can be used for determination of cyclosporine impurities in final dosage forms in pharmacetical QC laboratories. Keywords: cyclosporine....

The aim of diploma thesis has been development and optimization of method determination of N- nitrososarcosine and N-nitrosoproline in malt by gas chromatography with chemiluminiscence detector. Optimization of extraction method has been performed by response surface method. Quantification has been performed by internal standard method (N-nitrosopipecolic acid, in which matrix effects has been studied. These has been verified in münchen and pilsen malt, therefore matrix-matched calibration has been constructed. The developed method has been aplicated on wheat, münchen and pilsen malt. N- nitrosoproline was detected only in münchen malt and in other cases has been under limit of detection (LOD=4,0 µg/kg). N-nitrososarcosine was in all cases under limit of detection (LOD=3,7 µg/kg). The matrix-matched calibration has been constructed for experimental münchen malt with N-nitrosoproline concentration at 13,2 ± 2,9 µg/kg. Powered by TCPDF (www.tcpdf.org)

Utilisation of New Biomarkers for the Optimalization of Diagnostics and Therapy of Tumors of the Gastrointestinal Tract Introduction: Tumor markers are standard diagnostic tools. They are mainly used to monitor the course of the disease and to check the efficacy of the treatment. It is important to observe dynamics. Changing the level of the biomarker can prevent clinical manifestation and lead to early diagnosis of relapse, which in turn means improving the quality of life, including prolonging survival. Recently, we have encountered a number of diagnostic algorithms that suggest algorithms for estimating the risk of tumor presence or the risk of progression of cancer, using statistical methods. Objectives: The aim of this work is to verify new biomarkers for the diagnosis of gastric cancer and to develop an optimal algorithm for their use. Further, to evaluate the importance of cytokeratin markers - Tissue Polypeptide Antigen (TPA) and Tissue Polypeptide Specific Antigen (TPS) for the diagnosis of metastatic colorectal carcinoma in the liver. To carry out a pilot study of FGF23 levels in people with colorectal carcinoma and other gastrointestinal tumors. Methods and patients: Patient samples were analyzed using immunoradiometric, chemiluminescence and fluorescence assays. For each solved problem,...

One of the most relevant group of toxicologically significant compounds in beer are N-nitrosamines. In this thesis, the attention was paid especially on non-volatile nitroso compounds whose concentrations in beer, a chemical structure, and a biological effect has not been known yet. For the reason of the lack of knowledge regarding this compound group, the method for their sensitive detection by chemiluminescence detection after gas chromatographic separation was developed. This method permits a classification of detected nitroso compounds to different groups (N-nitroso, C-nitroso, and combination of C-nitroso and nitro) and distinguish them from interferences. The method is based on recording of a pyrolytic profile of each chromatographic peak, the profiles are then processed by discriminant analysis. The method has been developed for finding and structural identification purposes of these unknown compounds. Its application on an artificially nitrosated beer sample, together with gas chromatographic tandem mass spectrometric analysis, led to structural identification of several representatives of nitroso compounds. Sensory active compounds in this thesis are represented by carbonyl compounds and fatty acids. Carbonyl compounds - furfural and hydroxymethylfurfural - were used during the development...

Utilisation of New Biomarkers for the Optimalization of Diagnostics and Therapy of Tumors of the Gastrointestinal Tract Introduction: Tumor markers are standard diagnostic tools. They are mainly used to monitor the course of the disease and to check the efficacy of the treatment. It is important to observe dynamics. Changing the level of the biomarker can prevent clinical manifestation and lead to early diagnosis of relapse, which in turn means improving the quality of life, including prolonging survival. Recently, we have encountered a number of diagnostic algorithms that suggest algorithms for estimating the risk of tumor presence or the risk of progression of cancer, using statistical methods. Objectives: The aim of this work is to verify new biomarkers for the diagnosis of gastric cancer and to develop an optimal algorithm for their use. Further, to evaluate the importance of cytokeratin markers - Tissue Polypeptide Antigen (TPA) and Tissue Polypeptide Specific Antigen (TPS) for the diagnosis of metastatic colorectal carcinoma in the liver. To carry out a pilot study of FGF23 levels in people with colorectal carcinoma and other gastrointestinal tumors. Methods and patients: Patient samples were analyzed using immunoradiometric, chemiluminescence and fluorescence assays. For each solved problem,...