National Repository of Grey Literature 12 records found  1 - 10next  jump to record: Search took 0.01 seconds. 
Chemistry of polynitro heterocyclic compounds
Kubátková, Nela ; Bednařík, Karel (referee) ; Friedl, Zdeněk (advisor)
The review of polynitro heterocyclic compounds was written. These are substances with ability to detonate, which is caused mainly by presence of nitrogroups, which are bonded to carbon atoms in their cycles. The thesis deals with common polynitro five-membered heterocycles with one nitro atom, up to six-membered heterocycles with three nitrogen atoms. There are processed basic information of these compounds, as well as their physical-chemical properties and properties of detonation, the possibility of their preparation, which are displayed in the form of chemical reactions.
Study on stability of triazine based herbicides in water
Petrlíková, Kateřina ; Tesařová, Eva (advisor) ; Janečková, Lucie (referee)
The first aim of this thesis was to find a suitable analytical method for monitoring of stability of four s-triazine herbicides in water samples. Two columns - stationary phases C18, namely products of Waters and Astec were tested in HPLC system. The composition of ACN/H2O mobile phase was changed in the range from 90/10 to 60/40 (v/v). Baseline separation of prometone, propazine and prometryne was achieved on the Astec C18 column with mobile phase ACN/H2O 70/30 (v/v). This separation system was used for the study of stability. The stability of s-triazines was monitored in the period of six weeks. The samples of atrazine, prometone, propazine and prometryne water from water tap. All samples were detected at the wavelength of 221nm. No significant changes were found in the contents of s-triazines in the samples were measured in samples of water - water from Vltava, acidified water from Vltava, water from water tap and acidified water from water tap. All samples were detected at the wavelength of 221nm. No significant changes were found in the contents of s-triazines in the samples.
Hodnocení subchronického působení atrazinu na raka (Cherax destructor)
HLÁVKOVÁ, Markéta
The evaluation of the sub-chronic exposure to atrazine on crayfish The aim of this study is to evaluate the sub-chronic effect of atrazin on a behaviour, oxidative stress, antioxidant enzyme aktivities and biochemical profile of haemolymph in. These complex data should help to appraise the impact of this substance in the environment. The total test duration was 28 days and was divided into two periods. The first 14 days the crayfish were exposed to two concentrations of atrazine: 6.86 micrograms per liter (ATRenv = environmental concentration in the water in the Czech Republic) and 1.21 milligrams per liter (ATR10% = is coincident to 10% LC50). After the atrazine treatments the depuration 2 weeks phases in water without any chemicals followed. The results indicate that sub-chronic effect of atrazine influenced neither the behaviour of the crayfish nor the level of oxidative stress (measured by TBARS), whereas the changes of superoxiddismutase (SOD) were observed in all tissues (muscles, gills and hepatopancreas). The changes of enzyme activity were observed in catalase (CAT; hepatopancreas and the muscle tissue), glutathione S-transferase (hepatopancreas and the gills tissue), glutathione reductase (GR; the hepatopancreas tissue) and reduced glutathione (the muscle tissue). The influence of ATRenv on the biochemical profile of haemolymph at the following parameters was estimated only for lactate and alkaline, however phosphatase changes made by ATR10% were significant for glucose, ammonia, lactate and alkaline phosphatase measurements. The sub-chronical effect changed the activity of all antioxidant enzymes in hepatopancreas, muscles and the gills tissue of the observed crayfish. The presented results in this study are giving compact information of impact of atrazine on the crayfish and the whole water environment. The suggestion of using the crayfish for tests of toxicity looks like an ideal supplement for triazine herbicide estimations.
Study on stability of triazine based herbicides in water
Petrlíková, Kateřina ; Tesařová, Eva (advisor) ; Janečková, Lucie (referee)
The first aim of this thesis was to find a suitable analytical method for monitoring of stability of four s-triazine herbicides in water samples. Two columns - stationary phases C18, namely products of Waters and Astec were tested in HPLC system. The composition of ACN/H2O mobile phase was changed in the range from 90/10 to 60/40 (v/v). Baseline separation of prometone, propazine and prometryne was achieved on the Astec C18 column with mobile phase ACN/H2O 70/30 (v/v). This separation system was used for the study of stability. The stability of s-triazines was monitored in the period of six weeks. The samples of atrazine, prometone, propazine and prometryne water from water tap. All samples were detected at the wavelength of 221nm. No significant changes were found in the contents of s-triazines in the samples were measured in samples of water - water from Vltava, acidified water from Vltava, water from water tap and acidified water from water tap. All samples were detected at the wavelength of 221nm. No significant changes were found in the contents of s-triazines in the samples.
The effect of metabolite terbuthylazine-2-hydroxy on early life stages of marbled crayfish
PEŘINOVÁ, Eliška
Terbuthylazine belongs to the group of pesticides on triazine-based for use in agriculture as herbicides. Terbuthylazine-2-hydroxy is the main metabolite of terbuthylazine. The aim of this study was evaluate the effect of terbuthylazine-2-hydroxy on mortality, growth, occurrence the deformations and the development of early life stages, and levels of oxidative stress, assess the activity of antioxidant enzymes of marbled crayfish (Procambarus fallax f. virginalis) and also augment data for assessing the impact of this metabolite on the environment. For assess of effect of this metabolite was used embryo larval toxicity test with crayfish. The effect of terbuthylazine-2-hydroxy was evaluated in four concentrations (0.75 g.l-1, 75 g.l-1, 375 g.l-1 and 750 g.l-1) for 62 days. Terbuthylazine-2-hydroxy in concentrations 375 g.l-1 and 750 g.l-1 caused decrease of activity superoxide dismutase (SOD) and the levels lipid peroxidation (measured as TBARS) and inhibition of growth. Inhibition of growth was also observed in the group exposed to 75 g.l-1 of terbuthylazine-2-hydroxy. Additionally, there was delay in ontogenetic development of crayfish exposed to concentration 750 g.l-1. The real tested concentration of 75 g.l-1 terbuthylazine-2-hydroxy had no effect to monitored indices in the early life stages of marbled crayfish. Terbuthylazine-2-hydroxy caused oxidative damage of cellular lipids and proteins, changes in antioxidant activity, reduction of growth, delay in ontogenetic development of marbled crayfish.
Chemistry of polynitro heterocyclic compounds
Kubátková, Nela ; Bednařík, Karel (referee) ; Friedl, Zdeněk (advisor)
The review of polynitro heterocyclic compounds was written. These are substances with ability to detonate, which is caused mainly by presence of nitrogroups, which are bonded to carbon atoms in their cycles. The thesis deals with common polynitro five-membered heterocycles with one nitro atom, up to six-membered heterocycles with three nitrogen atoms. There are processed basic information of these compounds, as well as their physical-chemical properties and properties of detonation, the possibility of their preparation, which are displayed in the form of chemical reactions.
Establishment of method for determination of selected triazine pesticides in water using GC-MS/MS
OPEKAR, Jan
This bachelor thesis deals with the determination of triazine pesticides in water using GC-MS/MS. Firstly, the development and optimisation of an analytical method was performed. The following parameters of the analytical method were chosen for optimisation: carrier gas flow rate, temperature gradient, selection of SRM transitions and collision energy of SRM transitions. Then, several extraction parametres such as SPE column drying time, selection of elution solvent, sample pH and sample volume were optimised. Finally, the method was successfully validated and applied to the analysis of a real tap water sample.
The effect of metribuzine on oxidative stress and antioxidant enzymes of signal crayfish
LIDOVÁ, Jaroslava
The aim of this study was to investigate effects of the triazine herbicide metribuzine on oxidative stress level and antioxidant enzymes activity in gills, muscle and hepatopancreas of signal crayfish (Pacifastacus leniusculus Dana) and also extension of knowledge about effect of metribuzine on the environment. The experiment took up 60 days. Crayfish were exposured to metribuzine concentrations of 0.52 micrograms.l-1 (real environmental concentration) and 3.06 mg.l-1 (10% 96hLC50) for the first 30 days. Then a second phase followed depuration without metribuzine (30 days). Changes in the oxidative stress level (TBARS), superoxiddismutase (SOD) activity and catalase (CAT) activity were observed in all examined tissues. Changes in glutathionreductase (GR) activity were observed only in hepatopancreas. Chronic exposure of metribuzine demonstrated an oxidative damage of cell lipids, proteins and also changes in antioxidant activity in examined crayfish tissues.The results of this study suggest that crayfish are a very suitable organisms for toxicological tests and simultaneously extend knowledge about effect of metribuzine on the environment.
The effects of prometryne on early life stages of common carp
LIDOVÁ, Jaroslava
The effects of prometryne on early life stages of common carp Prometryne belongs to the triazine group of herbicides, which are used in agriculture. The aim of this study was to assess the impact of prometryne on mortality, occurrence of deformation, growth and development of early life stages of common carp (Cyprinus carpio L.). For assessing the impact of ryne on the early developmental stages of carp was used the method of embryo-larval toxicity test for fish (OECD test n. 210). Toxic effect of prometryne at four concentrations (0.51 micrograms.l-1, 80 micrograms.l-1, 1.2 mg.l-1 and 4 mg.l-1) was investigated during 35 days. Negative effects on mortality and growth were observed in the experimental group number four with the highest concentration of prometryne (4 mg.l-1). Retardation of ontogeny development of carp was observed in the experimental groups number three and four (concentrations 1.2 mg.l-1 and 4 mg.l-1). On the basic of test results was estimated at 35 day LC50 = 2,314 mg.l-1 prometryne. Based on mortality in experimental group was estimated LOEC = 1,10 mg.l-1 and NOEC = 0,85 mg.l-1 prometryne.

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