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Determination of sweeteners and preservatives in energy drinks by HPLC
Zídková, Anežka ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
This master´s thesis is focused on simultaneous determination of sweeteners and preservatives in energy drinks by liquid chromatography coupled with DAD and ELSD detection. The method was optimized for determination of aspartame, acesulfame K, saccharin, sucralose, steviol glycosides, benzoic acid and sorbic acid. Analyses were carried out on the Poroshell 120 EC-C18 column (4.6 x 150 mm, 2.7 m, Agilent) using mixture of methanol, acetone and water with formic acid and trimethylamine as a gradient mobile phase at a flow rate 0,5 mL•min-1. Validation parameters were determined (limit of detection, limit of quantification, repeatability and recovery). The validated method was applied on real samples.
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Removal of selected organic pollutants from water using advanced oxidation processes
Dalajková, Nikola ; Vávrová, Milada (referee) ; Repková, Martina (advisor)
The aim of this diploma thesis is the determination of selected organic pollutants with a focus on artificial sweeteners in waste water from wastewater treatment plant (WWTP) Modřice and the subsequent degradation of the thus obtained concentrations in model water using advanced oxidation processes (AOP). Two sweeteners were determined, namely sucralose and saccharin found in waste water. Synthetic sweeteners are not sufficiently cleaned in the WWTP and penetrate the environment. Effective processes for removing organic substances, including alternative sweeteners, are AOP processes. These processes are based on reactions of highly reactive hydroxyl radical (OH·), which is produced by many chemical reactions. Generally, they use ozone (O3) and hydrogen peroxide (H2O2). On sampling, wastewater samples were treated with Solid Phase Extraction (SPE) and then evaluated by HPLC/MS (High Performance Liquid Chromatography). In observing the degradation of selected sweeteners, three AOP methods were used: O3/UV, H2O2/UV and O3/H2O2. For each of these methods, the efficiency of degradation of sucralose and saccharin was investigated. From the evaluated data it was found that the most efficient AOP process for removing artificial sweeteners from water is the O3/H2O2 method.
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Determination of sweetener substitute content in chewing gum
Profousová, Sylvie ; Nábělek, Jakub (referee) ; Diviš, Pavel (advisor)
The bachelor thesis deals with the simultaneous determination of selected sweeteners in chewing gum by high-performance liquid chromatography with ELSD detection. The theoretical part is devoted to the characterization of carbohydrates and their effect on human health, classification, characterization of selected sweeteners and their use. Furthermore, a brief overview of analytical methods by which sweeteners can be determined is given. The experimental part focuses on the selection of a suitable chromatographic column for the simple identification of seven sweeteners (aspartame, acesulfame K, mannitol, maltitol, sucralose and xylitol) and the optimization of the mobile phase composition. It was found that it is not possible to determine all sweeteners by one universal method, however, using an Agilent Hi-Plex Ca column (300 x 7.7 mm) and the mobile phase of acetonitrile:water at 7:93 % v/v, it was possible to determine the concentration of (maltitol, mannitol, sorbitol, sucralose and xylitol). For the analysis of the individual sweeteners, different sample dilutions had to be used or the composition of the mobile phase had to be slightly changed. The concentration of artificial sweeteners in the chewing gum ranged from 0,35 mg/g (sucralose) to 508 mg/g (xylitol).
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Determination of sweetener substitute content in chewing gum
Profousová, Sylvie ; Nábělek, Jakub (referee) ; Diviš, Pavel (advisor)
The bachelor thesis deals with the simultaneous determination of selected sweeteners in chewing gum by high-performance liquid chromatography with ELSD detection. The theoretical part is devoted to the characterization of carbohydrates and their effect on human health, classification, characterization of selected sweeteners and their use. Furthermore, a brief overview of analytical methods by which sweeteners can be determined is given. The experimental part focuses on the selection of a suitable chromatographic column for the simple identification of seven sweeteners (aspartame, acesulfame K, mannitol, maltitol, sucralose and xylitol) and the optimization of the mobile phase composition. It was found that it is not possible to determine all sweeteners by one universal method, however, using an Agilent Hi-Plex Ca column (300 x 7.7 mm) and the mobile phase of acetonitrile:water at 7:93 % v/v, it was possible to determine the concentration of (maltitol, mannitol, sorbitol, sucralose and xylitol). For the analysis of the individual sweeteners, different sample dilutions had to be used or the composition of the mobile phase had to be slightly changed. The concentration of artificial sweeteners in the chewing gum ranged from 0,35 mg/g (sucralose) to 508 mg/g (xylitol).
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Determination of sweeteners and preservatives in energy drinks by HPLC
Zídková, Anežka ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
This master´s thesis is focused on simultaneous determination of sweeteners and preservatives in energy drinks by liquid chromatography coupled with DAD and ELSD detection. The method was optimized for determination of aspartame, acesulfame K, saccharin, sucralose, steviol glycosides, benzoic acid and sorbic acid. Analyses were carried out on the Poroshell 120 EC-C18 column (4.6 x 150 mm, 2.7 m, Agilent) using mixture of methanol, acetone and water with formic acid and trimethylamine as a gradient mobile phase at a flow rate 0,5 mL•min-1. Validation parameters were determined (limit of detection, limit of quantification, repeatability and recovery). The validated method was applied on real samples.
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Removal of selected organic pollutants from water using advanced oxidation processes
Dalajková, Nikola ; Vávrová, Milada (referee) ; Repková, Martina (advisor)
The aim of this diploma thesis is the determination of selected organic pollutants with a focus on artificial sweeteners in waste water from wastewater treatment plant (WWTP) Modřice and the subsequent degradation of the thus obtained concentrations in model water using advanced oxidation processes (AOP). Two sweeteners were determined, namely sucralose and saccharin found in waste water. Synthetic sweeteners are not sufficiently cleaned in the WWTP and penetrate the environment. Effective processes for removing organic substances, including alternative sweeteners, are AOP processes. These processes are based on reactions of highly reactive hydroxyl radical (OH·), which is produced by many chemical reactions. Generally, they use ozone (O3) and hydrogen peroxide (H2O2). On sampling, wastewater samples were treated with Solid Phase Extraction (SPE) and then evaluated by HPLC/MS (High Performance Liquid Chromatography). In observing the degradation of selected sweeteners, three AOP methods were used: O3/UV, H2O2/UV and O3/H2O2. For each of these methods, the efficiency of degradation of sucralose and saccharin was investigated. From the evaluated data it was found that the most efficient AOP process for removing artificial sweeteners from water is the O3/H2O2 method.
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