National Repository of Grey Literature 2 records found  Search took 0.00 seconds. 
Determination of Mercury in Hair by Atomic Fluorescence Spectrometry
Šandlová, Petra ; Červený, Václav (advisor) ; Hraníček, Jakub (referee)
The functionality of PS Analytical's Millenium Merlin Satellite external module to the PSA Millenium Excalibur atomic fluorescence spectrometer has been demonstrated on real samples. Hair was selected as real samples. In the first part, several extraction procedures were tested to obtain the highest response. The best results were obtained by the extraction method with TMAH and HCl in FIA-UV-PVG- AFS mode. In the next part, an attempt was made to optimize the conditions for the separation of mercury speciation, namely Hg2+ and MetHg. The optimized parameters were: the percentage of organic component in the mobile phase, the pH of the mobile phase, the flow rate of the added mobile phase per column, and the flow rate of the added 0.050M HCl per column. After this stage, 3 more extraction procedures were tested: extraction using L-cysteine with HCl, extraction using PDTC and extraction using DEDTC. However, none of the extraction procedures was better than the extraction method with TMAH and HCl. Despite the optimization of the method, the speciation of Hg in the hair samples failed because the chromatograms obtained did not match (even in retention times) those obtained for the mixture of standards with the mobile phase extraction reagents. Subsequently, the conditions for the determination of total...
Comparison of mercury determination by electrochemical or UV-photochemical vapor generation with detection by atomic fluorescence
Šandlová, Petra ; Červený, Václav (advisor) ; Nováková, Eliška (referee)
~ 5 ~ Abstract The functionality of the add-on Millennium Merlin Satellite module towards the PSA Millennium Excalibur atomic fluorescence spectrometer for determination of mercury has been proven. At the same time, the ratios of the average signal to the sample standard deviations of the results of repeated measurements of this module were compared with the mercury determination using an atomic absorption spectrometer ContrAA700 with a radiation source with continuous spectrum and high resolution. In model experiments performed on an atomic absorption spectrometer, the experimental conditions of the cold vapor detection above the level of the elemental mercury were optimized. The flow rate of argon and hydrogen, the temperature of the detection cell and the storage bottle and the mercury evaporation time were optimized. It has been shown that the reduction environment in the detection tube reduces the signal. The need to heat the detection tube up to 650 řC has been surprising. The causes of this phenomenon were discussed and confronted with data from the available literature. Subsequently, the mercury signal was monitored unde roptimal conditions found on the AAS, using an atomic fluorescence PSA Millennium Excalibur spectrometer with an additional Millennium Merlin Satellite unit for mercury...

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