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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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QSAR Analysis of the Acute Toxicity Indices Determined by Alternative Methods
Kanásová, Mária ; Rucki, Marian (advisor) ; Dvořáková, Markéta (referee)
1 Abstract The goal of the thesis is to determine acute toxicity indices of seven alcohols (2-ethoxyethanol, 1-propanol, 3-methyl-1-butanol, 3-methyl-2-butanol, 3-hexanol, 2-methyl-3-hexanol, 1-nonanol) by two different alternative methods. Another goal is to create QSAR models to predict the acute toxicities of alcohols which belong into model limits. First of the methods used is based on the movement inhibition of lower animals Tubifex tubifex. The method provides the acute toxicity indices EC50. The second method uses the cell line of mouse fibroblasts called Balb/c 3T3 and it provides the acute toxicity indices IC50. The IC50 were recalculated to the LD50 values that correspond to the oral administration of alcohols to a rat. It has been found that 1-nonanol is included into the category of alcohols classified as acute oral toxic according to the EU CLP system. Other six alcohols are non-classified as acute oral toxic. Subsequently, accurate QSAR models has been created in order to predict the acute toxicity of other alcohols using Tubifex tubifex specie or Balb/c 3T3 cell line. The models are suitable for saturated, branched, ethoxy- and cyclic alcohols with the log POW value from −0.74 to 3.07. It was necessary to exclude the acute toxicity indices of 1-nonanol from these models as some solubility...
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QSAR Analysis of the Acute Toxicity Indices Determined by Alternative Methods
Kanásová, Mária ; Rucki, Marian (advisor) ; Dvořáková, Markéta (referee)
1 Abstract The goal of the thesis is to determine acute toxicity indices of seven alcohols (2-ethoxyethanol, 1-propanol, 3-methyl-1-butanol, 3-methyl-2-butanol, 3-hexanol, 2-methyl-3-hexanol, 1-nonanol) by two different alternative methods. Another goal is to create QSAR models to predict the acute toxicities of alcohols which belong into model limits. First of the methods used is based on the movement inhibition of lower animals Tubifex tubifex. The method provides the acute toxicity indices EC50. The second method uses the cell line of mouse fibroblasts called Balb/c 3T3 and it provides the acute toxicity indices IC50. The IC50 were recalculated to the LD50 values that correspond to the oral administration of alcohols to a rat. It has been found that 1-nonanol is included into the category of alcohols classified as acute oral toxic according to the EU CLP system. Other six alcohols are non-classified as acute oral toxic. Subsequently, accurate QSAR models has been created in order to predict the acute toxicity of other alcohols using Tubifex tubifex specie or Balb/c 3T3 cell line. The models are suitable for saturated, branched, ethoxy- and cyclic alcohols with the log POW value from −0.74 to 3.07. It was necessary to exclude the acute toxicity indices of 1-nonanol from these models as some solubility...
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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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Toxicity determination of polyfluorinated and perfluorinated organic substances
Otrubová, Lucie ; Čabala, Radomír (advisor) ; Rucki, Marian (referee)
The goal of the bachelor thesis was the determination of toxicity of fluorotelomer alcohols. The toxicity was measured as ET50 by the oligochaete Tubifex tubifex. This test belongs to group of alternative methods which are faster and cheaper but they provide reliable data as well as the presently used classical methods. ET50 is the exposure time when 50 % of Tubifex tubifex individuals stop moving. EC50 of magnese chloride dihydrate was measured for the control of its correctness of determination and its acute toxicity indice is equal to log (EC50) = -0,845 ± 0,033 [log (mmol/l)]. EC50 is the concentration of the tested substance when 50 % of Tubifex tubifex individuals stop moving. 1H,1H,2H,2H-perfluorooctan-1-ol and 1H,1H,2H,2H-perfluorodecan-1-ol were the tested substances. Destilled water and solution of dimethyl sulfoxide in water (5 %) were used to prepare the saturated solutions of the tested substances. The conncentrations of the saturated solutions were determined on GC-MS by absolute calibration method. The value of log (EC50) for dimethyl sulfoxide solution was measured to determine how it influences Tubifex tubifex during exposure time of 2,5 hours. KEY WORDS: fluorotelomer alcohols, alternative method, Tubifex tubifex
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