|
|
Multicomponental Preconcentration of As, Sb, Se and Te on Modified Silica, Their Determination by ICP-AES (ICP-MS) and Application for Waters
Urbánková, Kristýna ; Řehůřková, Irena (referee) ; Kanický, Viktor (referee) ; Ventura, Karel (referee) ; Sommer, Lumír (advisor)
The determination of inorganic speciations of arsenic, antimony, selenium and tellurium in natural waters demands often separation and preconcentration. Solid phase extraction is a very effective method for these purposes. In this paper the separation and preconcentration of these microelements is realised on the basis of modified silica Separon SGX C18, SGX C8, SGX CN, SGX NH2, SGX Phenyl and strongly basic anion Exchanger SGX AX. The sorption was provided in the presence of cationic surfactants such as benzyldimethyl dodecylammonium bromide (Ajatin), benzyldimethyltetradecylammonium chloride (Zephyramine), 1-ethoxycarbonylpentadecyltrimetrhylammonium bromide (Septonex) and selected complexing agents 4-(2-pyridylazo)resorcinol (PAR), 8-hydroxyquinoline-5-sulphonic acide (8-HQS), 1,2-dihydroxybenzene (PYR), amonium 1-pyrrolidinecarbodithioate (APDC), sodium diethyldithiocarbamate (DTC) or thiourea(Thur). The interactions of the formed ion associate with the sorbent shows a complicated character which has not been cleared as yet. The previous conditioning of the sorbent plays an outstanding role. Thus, the sorption efficiency was studied in the presence and absence of surfactant and of selected organic complexing agents. Moreover, the influence of pH of the sorbed solution as well as the speed and the volume of the solution running through the sorbent and the type and volume of the eluent on the resulting sorption efficiency was evaluated. The sorption was successfully carried out from 50-1000 ml of solution which allows the 100 fold increase of the preconcentration factor and the determination of the microelements in g.l-1 instead of mg.l-1 by using the common ICP-AES. The influence of macroelements occurring in waters as well as B, Be, Bi, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sr, Ti, V and Zn in comparable concentrations involve less than 5% error. After the quantitative elution of microelements, the organic solvents were evaporated under IR lamps prior to the determination by ICP-AES and |ICP-MS. The conditions for the direct determination of arsenic, antimony, selenium and tellurium in g.l-1 with ICP-MS were also described in detail in the absence and presence of internal standards Ge and Bi. However, even in this case the preconcentration on silica in the presence of surfactant and selected organic complexants was also tested. When the sorption was followed from 500 ml a 50 fold enrichment factor is reached and the sensitivity for the microelements is improved. The direct determination and the sorption of microelements were applied on synthetic and real waters (dirinking, surface, mineral and sea waters). Instrumental and practical detection limits for various water samples were evaluated according to IUPAC. The results from 1000 ml solution of real waters after sorption on modified silica and the final determination of microelements with ICP-AES were compared with those from ICP-MS without sorption using the method of standards addition in the presence of suitable internal standards. By comparison of results for synthetic and real water samples the error of the determination of microelements was evaluated.
|
|
|
Influence of diclofenac on naproxene phytoextraction.
Urbánková, Kristýna ; Smrček, Stanislav (advisor) ; Břichnáčová Habartová, Věra (referee)
The presence of organic compounds from commonly used pharmaceuticals in surface waters is considered to be pseudo-persistent contamination with possible negative biological effects. One of the methods for limited entering of these compounds into ecosystem is using biotechnological processes for secondary treatment of sewage treatment plants effluent. Phytoextraction of naproxene and diclofenac was observed in plants like sunflower, maize and rape using in vitro experiments under different conditions monocomponent and dicomponent artificial pollution. In the experiments with individual substances the ability of phytoextraction was found in all cases. Contrary to results with maize, sunflower has different phytoextraction ability for naproxene and diclofenac (80 % vs. 34 % of extracted naproxene and diclofenac after 24 hours of experiment) and amounts of extracted material are dependent on used cultivar. In case of rape the difference between both tested substances is not so big (5 % of naproxene vs. 33 % of diclofenac). Generally naproxene is phytoextracted more easily from the medium, whereas the presence of diclofenac decreased uptake of naproxene in all tested cultivars.
|
|
|
Influence of diclofenac on naproxene phytoextraction.
Urbánková, Kristýna ; Smrček, Stanislav (advisor) ; Břichnáčová Habartová, Věra (referee)
The presence of organic compounds from commonly used pharmaceuticals in surface waters is considered to be pseudo-persistent contamination with possible negative biological effects. One of the methods for limited entering of these compounds into ecosystem is using biotechnological processes for secondary treatment of sewage treatment plants effluent. Phytoextraction of naproxene and diclofenac was observed in plants like sunflower, maize and rape using in vitro experiments under different conditions monocomponent and dicomponent artificial pollution. In the experiments with individual substances the ability of phytoextraction was found in all cases. Contrary to results with maize, sunflower has different phytoextraction ability for naproxene and diclofenac (80 % vs. 34 % of extracted naproxene and diclofenac after 24 hours of experiment) and amounts of extracted material are dependent on used cultivar. In case of rape the difference between both tested substances is not so big (5 % of naproxene vs. 33 % of diclofenac). Generally naproxene is phytoextracted more easily from the medium, whereas the presence of diclofenac decreased uptake of naproxene in all tested cultivars.
|
|
|
Development of foreign trade with wine in the Czech Republic
Urbánková, Kristýna ; Regnerová, Olga (advisor) ; Zdeněk, Zdeněk (referee)
The topic of this diploma thesis is Development of foreign trade with wine in the Czech Republic and it analyses the evolution of foreign trade with wine in the Czech Republic, specifically since 2005 until now. This diploma thesis consists of two part.
The first, theoretical, part is processed based on secondary resources and focuses on wine characteristics, history and the evolution of wine-making. It provides information about important wine-making regions such as Bohemia and Moravia, classification and division of wines as well as important wine-making organisations. This part is also focused on complete information regarding foreign trade with wine.
The practical part is focused on an analysis of evolution of foreign trade with wine from the accession of Czech Republic to the European Union until now. Each year is thoroughly described. This part of the thesis is also focused on wine consumption in the Czech Republic and there is also a short outlook to the future.
All findings are described in detail and summarized in clear tables and graphs. The conclusion of this thesis is focused on an overall summary and evaluation of the results.
|
|
|
Multicomponental Preconcentration of As, Sb, Se and Te on Modified Silica, Their Determination by ICP-AES (ICP-MS) and Application for Waters
Urbánková, Kristýna ; Řehůřková, Irena (referee) ; Kanický, Viktor (referee) ; Ventura, Karel (referee) ; Sommer, Lumír (advisor)
The determination of inorganic speciations of arsenic, antimony, selenium and tellurium in natural waters demands often separation and preconcentration. Solid phase extraction is a very effective method for these purposes. In this paper the separation and preconcentration of these microelements is realised on the basis of modified silica Separon SGX C18, SGX C8, SGX CN, SGX NH2, SGX Phenyl and strongly basic anion Exchanger SGX AX. The sorption was provided in the presence of cationic surfactants such as benzyldimethyl dodecylammonium bromide (Ajatin), benzyldimethyltetradecylammonium chloride (Zephyramine), 1-ethoxycarbonylpentadecyltrimetrhylammonium bromide (Septonex) and selected complexing agents 4-(2-pyridylazo)resorcinol (PAR), 8-hydroxyquinoline-5-sulphonic acide (8-HQS), 1,2-dihydroxybenzene (PYR), amonium 1-pyrrolidinecarbodithioate (APDC), sodium diethyldithiocarbamate (DTC) or thiourea(Thur). The interactions of the formed ion associate with the sorbent shows a complicated character which has not been cleared as yet. The previous conditioning of the sorbent plays an outstanding role. Thus, the sorption efficiency was studied in the presence and absence of surfactant and of selected organic complexing agents. Moreover, the influence of pH of the sorbed solution as well as the speed and the volume of the solution running through the sorbent and the type and volume of the eluent on the resulting sorption efficiency was evaluated. The sorption was successfully carried out from 50-1000 ml of solution which allows the 100 fold increase of the preconcentration factor and the determination of the microelements in g.l-1 instead of mg.l-1 by using the common ICP-AES. The influence of macroelements occurring in waters as well as B, Be, Bi, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sr, Ti, V and Zn in comparable concentrations involve less than 5% error. After the quantitative elution of microelements, the organic solvents were evaporated under IR lamps prior to the determination by ICP-AES and |ICP-MS. The conditions for the direct determination of arsenic, antimony, selenium and tellurium in g.l-1 with ICP-MS were also described in detail in the absence and presence of internal standards Ge and Bi. However, even in this case the preconcentration on silica in the presence of surfactant and selected organic complexants was also tested. When the sorption was followed from 500 ml a 50 fold enrichment factor is reached and the sensitivity for the microelements is improved. The direct determination and the sorption of microelements were applied on synthetic and real waters (dirinking, surface, mineral and sea waters). Instrumental and practical detection limits for various water samples were evaluated according to IUPAC. The results from 1000 ml solution of real waters after sorption on modified silica and the final determination of microelements with ICP-AES were compared with those from ICP-MS without sorption using the method of standards addition in the presence of suitable internal standards. By comparison of results for synthetic and real water samples the error of the determination of microelements was evaluated.
|
guest ::
RSS feed.