National Repository of Grey Literature 2 records found  Search took 0.00 seconds. 
Application of a commercial multimode sample introduction system as a generator of volatile compounds
Hadbavníková, Alexandra ; Nováková, Eliška (advisor) ; Červený, Václav (referee)
EN The main goal of this thesis was the determination of zinc using a commercial multimode sample introduction system (MSIS) as a generator of volatile compounds with inductively coupled plasma mass spectrometer as detector. The generation of volatile compounds took place using sodium borohydride in an acid environment. In the first step of the experiment, the following parameters affecting the generation of volatile compounds were optimized: acid selection, acid concentration, sodium hydroxide concentration, mass concentration of sodium borohydride, mass concentration of 8-hydroxyquinoline, volume of the injection loop and flow rates of sample, carrier gas and hydrogen. Subsequently, figures of merit of the method were determined under optimal conditions. The limit of detection was 2.8 μg·dm-3 and the limit of quantification was 9.3 μg·dm-3 . Generation efficiency of the volatile zinc compound was determined as 3.7 %, which is the highest efficiency yet achieved for this element and generation system in this laboratory. Interference studies did not demonstrate the ability of any of the tested hydride-forming or transition elements to act as a modifier increasing the generation efficiency, but at the same time, none of the investigated elements proved to be a significant interferent. Key words...
Determination of Copper in Food Supplements by AAS
Hadbavníková, Alexandra ; Hraníček, Jakub (advisor) ; Nováková, Eliška (referee)
EN This bachelor thesis deals with the determination of copper in the form of copper ions in selected food supplements by atomic absorption spectrometry. The first step of the experiment was to find the optimal measurement conditions for the parameters: beam height above the burner edge, burner horizontal position, fuel flow rate, burner angle and spectral interval width. Subsequently, the calibration dependence was determined and the basic measurement characteristics were calculated: repeatability, sensitivity, limit of detection (0.019 mg dm−3 ) and limit of quantification (0.065 mg dm−3 ) at the burner position 0 ř. Interference studies were performed for the presence of iron, manganese and sodium elements in selected food supplements because of theirs increased concentrations. These selected food supplements were analysed: Spektrum 50, Supradyn Energy Complex, Center from A to iron, GS Extra Strong Multivitamin, Caltrate Plus, DAS Gesunde Plus, A-Z Multispektrum and Calibrum 50 Plus. Selected samples were converted to solutions using three procedures: decomposition in water at room temperature, decomposition in nitric acid at room temperature and decomposition in nitric acid at high temperature. The determination of copper itself was performed using a GBC 933 AA spectrometer and the results...

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