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Determination of n-octanol/water partition coefficient (Kow) of perfluorinated acids
Skrottová, Anežka ; Rucki, Marian (advisor) ; Tichý, Miloň (referee)
Perfluorinated compounds are organic compounds in which all hydrogen atoms in a carbon chain are substituted with fluorine atoms. These compounds are highly stable, persistent and bioaccumulative. They are purely anthropogenic compounds contained in biota and abiota. Partition coefficient between n-octanol and water is the essential toxicological parameter of a compound. This parameter helps us to assess behaviour of compound in the environment as well as in the living organisms. The shake flask method and the RP-HPLC method were employed to measure the Kow of nine perfluorinated acids. Using the shake flask method, the surface activity of compounds and the acid dissociation caused false results of the measurement. But behaviour of these compounds in the environment can be assess. Accurate and precise results were measured by the RP-HPLC method using an acetate buffer. Log Kow of perfluoro- carboxylic acids, with the carbon chain length of 5-14, were found out, their final value ranging between 1.66 and 5.10. Log Kow of acid with 12 carbons was estimated based on the linear regression of dependence of log Kow on the number of carbons. There were significant differences in the results obtained by various software. Thus, the results cannot be considered relevant. These software are not suitable for...
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Determination of n-octanol/water partition coefficient (Kow) of perfluorinated acids
Skrottová, Anežka ; Rucki, Marian (advisor) ; Tichý, Miloň (referee)
Perfluorinated compounds are organic compounds in which all hydrogen atoms in a carbon chain are substituted with fluorine atoms. These compounds are highly stable, persistent and bioaccumulative. They are purely anthropogenic compounds contained in biota and abiota. Partition coefficient between n-octanol and water is the essential toxicological parameter of a compound. This parameter helps us to assess behaviour of compound in the environment as well as in the living organisms. The shake flask method and the RP-HPLC method were employed to measure the Kow of nine perfluorinated acids. Using the shake flask method, the surface activity of compounds and the acid dissociation caused false results of the measurement. But behaviour of these compounds in the environment can be assess. Accurate and precise results were measured by the RP-HPLC method using an acetate buffer. Log Kow of perfluoro- carboxylic acids, with the carbon chain length of 5-14, were found out, their final value ranging between 1.66 and 5.10. Log Kow of acid with 12 carbons was estimated based on the linear regression of dependence of log Kow on the number of carbons. There were significant differences in the results obtained by various software. Thus, the results cannot be considered relevant. These software are not suitable for...
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Determination of distribution coefficients of perfuorinted compounds in 1-octanole/water system
Skrottová, Anežka ; Čabala, Radomír (advisor) ; Nesměrák, Karel (referee)
The aim of the bachelor thesis was to determinate distribution coefficients of 1H,1H,2H,2H-Perfluoro-1-octanol and 1H,1H,2H,2H-Perfluoro-1-decanol in 1-octanol/water system. Method used for measurement was the shake flask method. Measured substance is distributed between two immiscible liquids after intensive shaking. Concentration in both phases was measured after equilibration with Gas Chromatography - Mass Spectrometry. Knowledge of distribution coefficients helps to estimate toxic potential of substance. Logarithm of distribution coefficient of measured substances was about 3,5. It means, that measured substances are lipophilic. It is associated with their high bioaccumulation potential. They accumulate in organism and their excretion is very difficult. They also accumulate in abiotic environment. So they have negative effects on it and their production is reduced.
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