Speciace rtuti v sedimentech HPLC-AFS

Bc. Jana Novotná

Master's thesis

Abstract:

Byla provádna izolace forem rtuti v pírodních sedimentech za použití extrakce ultrazvukem a v mikrovlnném poli v pítomnosti extrakního inidla (HCl, HCl + NaCl, H2SO4 + KBr, atd.). Nejvtší výtžek byl dosažen použitím roztoku 6M HCl a 1M NaCl. Mikrovlnnou extrakcí (pi teplot 58C) bylo dosaženo o 1,5 % celkového obsahu rtuti (THg) více než pi použití ultrazvuku. Obsah celkové rtuti v sedimentech byl stanoven použitím analyzátoru AMA 254. Obsah celkové rtuti ve vybraných sedimentech inil 0,019 0,707 mg.g-1. Pro separaci a stanovení anorganických specií rtuti a methylrtuti byl použit systém HPLC-CV-AFS. Methylrtu tvoila až 18,6 % z celkového obsahu rtuti v sedimentu. Byl sledován vliv nkterých faktor (pH, iontová síla, koncentrace HCl, as) na uvolování rtuti ze sedimentu ve vodném prostedí a schopnost sedimentu zachytit rtu. pH a iontová síla nemají významný vliv na uvolování rtuti ze sedimentu do vodného prostedí. Uvolnní rtuti roste s rostoucí koncentrací HCl v roztoku i s dobou psobení kyselého roztoku. Schopnost sedimentu zachytit anorganickou formu rtuti a methylrtuti z roztoku je rzná. Tato schopnost byla sledována u 6 systém sedimentu v roztoku s rzným obsahem tchto forem rtuti.

Abstract:

Sonication and microwave-assisted extractions in the presence of extraction agents (HCl, HCl + NaCl, H2SO4 + KBr, etc.) were tested for the isolation of mercury species from the natural sediments. The mixture of 6M HCl and 1M NaCl was selected as the most suitable extraction agent. The extraction efficiency was about 1.5 % higher when optimised microwave-assisted (used 58 C) extraction was applied instead of sonication. The total mercury (THg) concentrations in sediments were determined by using an Advanced Mercury Analyser AMA 254. The sediments contented 0.019 0.707 mg.g-1 of the total mercury. HPLC-CV-AFS was used for the separation and determination of inorganic mercury species and methylmercury. MeHg+ constituted as many 18.6 % of THg in sediment. The factors (pH, ion power, concentration of HCl, time) influencing the relaxation of mercury from sediment in aquatic surrounding and the capability of sediment to catch the mercury species was observed. pH and ion power (the extent 0.1 1) had not an important influence on the relaxation of mercury from sediment in aquatic surrounding. The relaxation of mercury from sediment grew with the increasing concentration of HCl and with the increasing time. The sediment had the capability to catch the inorganic species of mercury and methylmercury in solution different. It was observed in 6 different systems of the sediment in the solution.

Keywords

Methylrtu, celkový obsah rtuti, sediment, mikrovlnná extrakce, atomová absorpní spektrometrie, kapalinová chromatografie, atomová fluorescenní spektrometrie. Methylmercury, Total mercury, Microwave-assisted extraction, Atomic absorption spectrometry, Liquid chromatography, Atomic fluorescence spectrometry.

Language used: Czech

Date on which the thesis was submitted / produced: 26. 5. 2006

Thesis defence

• Date of defence: 8. 6. 2006
• Supervisor: prof. RNDr. Josef Komárek, DrSc.

Masaryk University

Faculty of Science

Master programme / field:
Chemistry / Analytical Chemistry