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Optimization of experimental conditions for measurements of perfluorinated organic acids by GC
Ston, Martin ; Čabala, Radomír (advisor) ; Coufal, Pavel (referee)
Commercial software Pro ezGC was used for calculation of optimal temperature program for analysis of isobutylesters of perfluorinated organic acids (C6 - C12) by gas chromatography with flame ionization detector. Optimization was done with respect to the complete resolution of all peaks of analytes. The calculated temperature program was also applied to the analysis of substances of interest on GC-MS. The calculated and measured values have been compared. The measured resolutions were higher than the calculated ones in all cases. Keywords: perfluorinated organic acids, isobutylesters, peak resolution Subject words: gas chromatography, numerical optimization
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Testing and optimization of pressure modulator conditions for GCxGC analyses
Ston, Martin ; Čabala, Radomír (advisor) ; Jelínek, Ivan (referee)
Pulse (fluid) pressure modulator was constructed for comprehensive gas chromatography. Optimal conditions of its connection to the gas chromatograph with a flame ionization detector were found for the analysis of selected mixture of volatile solvents. Pressure interdependences in the system and relations between dimensions of modulator capillaries and columns have been evaluated with respect to the length of the modulation period and pulse duration. Two non-polar columns (15 m × 0.25 mm DB-5MS, 10 m × 0.15 mm CP-Sil 5 CB) of the same stationary phase were tested to compare the separation efficiency in the first dimension and the DB-5MS column was selected. The Supelcowax 10 columns of the lengths 1, 2 and 3 m were compared in the second dimension. It was found that using of 3 m length column lead to the extension of analysis time, however the increase in separation efficiency in the second dimension was very evident. The experimental measurements have shown that the selected parameters for the evaluation of the separation efficiency (the peak capacity and total resolution product) were inappropriate. Gasoline, kerosene and diesel fuel were analyzed as examples of real samples. Amount of added ethanol as a biofuel additive was determined in the gasoline sample. Pulse pressure modulator was modified...
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Mathematical modelling of linear and nonlinear phenomena in capillary electrophoresis
Dvořák, Martin ; Dubský, Pavel (advisor) ; Kašička, Václav (referee) ; Gebauer, Petr (referee)
Capillary electrophoresis is one of the prominent analytical separation methods. Currently, many computer programs exist which are able to predict the result of an electrophoretic experiment. Firstly, there are programs based on numerical solving of corresponding continuity equations and equations of chemical equilibria. Secondly, there are programs based on approximative models of capillary electrophoresis. Programs belonging to the first group are applicable to a wide range of modes of capillary electrophoresis and provide a precise solution. Their disadvantage is though a considerable time demand. On the other hand, the approximative models give the results almost immediately and, in addition, provide some theoretical relationships which are useful for optimization of the separation process. This dissertation thesis is focused on improvement and extension of validity of existing approximative models of capillary electrophoresis. As a part of this thesis, a model capable of a full-blown description of capillary electrokinetic chromatography is introduced. This model is implemented into program PeakMaster 6. The attention is also paid to a nonlinear model of electromigration without diffusion. This model enables a very good description of electromigration dispersion including effects related to...
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Testing and optimization of pressure modulator conditions for GCxGC analyses
Ston, Martin ; Čabala, Radomír (advisor) ; Jelínek, Ivan (referee)
Pulse (fluid) pressure modulator was constructed for comprehensive gas chromatography. Optimal conditions of its connection to the gas chromatograph with a flame ionization detector were found for the analysis of selected mixture of volatile solvents. Pressure interdependences in the system and relations between dimensions of modulator capillaries and columns have been evaluated with respect to the length of the modulation period and pulse duration. Two non-polar columns (15 m × 0.25 mm DB-5MS, 10 m × 0.15 mm CP-Sil 5 CB) of the same stationary phase were tested to compare the separation efficiency in the first dimension and the DB-5MS column was selected. The Supelcowax 10 columns of the lengths 1, 2 and 3 m were compared in the second dimension. It was found that using of 3 m length column lead to the extension of analysis time, however the increase in separation efficiency in the second dimension was very evident. The experimental measurements have shown that the selected parameters for the evaluation of the separation efficiency (the peak capacity and total resolution product) were inappropriate. Gasoline, kerosene and diesel fuel were analyzed as examples of real samples. Amount of added ethanol as a biofuel additive was determined in the gasoline sample. Pulse pressure modulator was modified...
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Optimization of experimental conditions for measurements of perfluorinated organic acids by GC
Ston, Martin ; Coufal, Pavel (referee) ; Čabala, Radomír (advisor)
Commercial software Pro ezGC was used for calculation of optimal temperature program for analysis of isobutylesters of perfluorinated organic acids (C6 - C12) by gas chromatography with flame ionization detector. Optimization was done with respect to the complete resolution of all peaks of analytes. The calculated temperature program was also applied to the analysis of substances of interest on GC-MS. The calculated and measured values have been compared. The measured resolutions were higher than the calculated ones in all cases. Keywords: perfluorinated organic acids, isobutylesters, peak resolution Subject words: gas chromatography, numerical optimization
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