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Pyrethroids in abiotic and biotic environmental matrices
Kociánová, Veronika ; Vondráčková, Ilona (referee) ; Vávrová, Milada (advisor)
Synthetic pyrethroids form the main class of synthetic organic insecticides, which are applied in agriculture, household, and public health. Synthetic pyrethroids account form more than 30% of insecticide use worldwide, thereby they gradual replace chemicals of insect pest control as organochlorine and organophosphate insecticides. Pyrethroids are synthetic derivates of natural pyrethrins. In comparison with natural pyrethrins have pyrethroids greater photostability, greater resistence to degradation and greater insecticidal activity. Pyrethroids are labeled as potent neurotoxicants, which interact with sodium channels. Pyrethroids occur in abiotic and biotic environmental matrices. In this study we focused on the determination of this compounds in environmental water samples by GC-ECD, because of the pyrethroids contain atoms of nitrogen and halogens in their structure.
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Degradation of pyrethroids using heterogeneous catalysts
Janík, Ondřej ; Bílková, Zuzana (referee) ; Vávrová, Milada (advisor)
This thesis was provided to study fotocatalytic degradation of polutants on the titanium dioxide, as modern eliminating method useful for removing of polutants out of the environmental matrix. There are also studied pyrethroids, as one of the most used pesticides in recent ages, and posibility of degradation of pyrethroids using degradation on titanium dioxide in aquatic system. This study contains an experiment of fotocatalytic degradation of pyrethroids on titanium dioxide in vitro with final analysis using GC-ECD.
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Rezistence brouků škodících na obilninách k vybraným účinným látkám insekticidů
Benda, Ivo
The thesis titled “The Resistance of Beetles Harmful to Cereals Towards Selected Active Substances of Insecticides” deals with the issue of sensitivity of the oulema cereal leaf beetles towards active substances from the pyrethroid category (lambda-cyhalothrin) and organophosphates (chlorpyrifos-ethyl). Research was performed at a number of locations in the region of South Moravia. The beetles were collected on fields with common wheat (Triticum aestivum) and barley (Hordeum vulgare). The testing of the beetles was performed in a lab using the adult-vial test. Imagos were exposed to four concentrations of each active substance in three repetitions. The results were processed using the Polo Plus program. The activity of the beetles differed depending on the concentration of the active substance.
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The early molecular detection of resistance in populations of pollen beetle
WALTEROVÁ, Lucie
The thesis deals with molecular detection of resistance in populations of pollen beetle based on genetic polymorphisms in the VSSC gene of this pest. Population samples were collected in 2016-2018 in the Czech Republic, mainly in the Southwestern Bohemian Region. A total of 57 populations of pollen beetles with different degrees of resistance were analyzed. Nucleotide mutations of populations were monitored in two parts of the VSSC gene of pollen beetles - DIIS4 - S5 linker / DIIS5 and DIIIS6 gene, which is located in the VSSC binding domain. These parts were amplified and sequenced by the Sanger method. In the alignment of final sequences, mutations were searched. After that, the effect of these mutations on the amino acid sequence was determined and the effect on the resulting VSSC protein conformation was assessed.
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The effect of pyrethroid based pesticides on fish
RICHTEROVÁ, Zuzana
Pyrethroids are ones of the most used pesticides worldwides. The widespread use and high stability of pyrethroids lead to the assumption of that their occurrence in the environment could be quite frequent. They can reach water ecosystem as pollutants. Residues of pyrethroids are not only detected in the water column, but also in sediments and in fish tissues. The first study was devoted to the product Nexide containing 60 g.l-1 of active substance gamma-cyhalothrin. Tested Nexide concentrations were 5, 25, 50, 100, and 250 µg.l-1. Early life stage test was used.Common carp (Cyprinus carpio) was tested. There were significant mortalities in all concentrations except the lowest concentration during the trial. The lowest concentration tested 5 µg.l-1 only caused a slightly increased mortality. This lowest concentration influenced the growth in length and weight negatively, decelerated ontogenetic development, and made the body surface of the individuals darker. Histopathology of individuals from this concentration revealed dystrophy in liver. Examination of kidney, intestine and gills did not show significant histopathological differences compared with control. The evaluation of selected parameters of oxidative stress demonstrated a significantly higher activity of detoxification enzyme glutathione-S.transferase (GST) and a significantly lower activity of defensive enzyme glutathione peroxidase (GPx) compared with the control group. The other examined parameters of oxidative stress such as catalase (CAT), glutation reductase (GR), and lipid peroxidation determined by using the thiobarbituric acid-reactive substances (TBARs) were comparable to the control group. Changes in oxidative stress parameters suggest that exposure of the organism to the product Nexide in the given concentration leads to dysbalance of defensive enzymes. The second study was devoted to the product Cyperkill 25 EC containing 250 g.l-1. Tested Cyperkill 25 EC concentrations were 7.2, 36, 72, 144, and 360 µg.l-1. The procedure of the trial was the same as the preceded one. There were 100% mortalities in all concentrations except the lowest concentration during the trial. The lowest tested concentration 7.2 µg.l-1 allowed 90% of individuals to stay alive till the end of experiment. The lowest concentration influenced the growth in length and weight negatively and decelerated ontogenetic development compared with the control. Any individual exposed to this concentration did not reach juvenile stage until the end of the trial. Dark pigmentation was visible in 68% of these exposed individuals on the last day. Similar darkening was visible in individuals from higher concentrations shortly before death too. Histological examination did not revealed significant changes in intestine, liver, kidney, and gills compared with the control group. Evaluation of selected parameters of oxidative stress demonstrated significantly lower activities of GST, GR, and GPx. Activities of CAT and TBARS were comparable with the control group. Changes in oxidative stress parameters suggest that exposure of the organism to the product Cyperkill 25 EC in the given concentration could induce oxidative stress and interfere with the activities of antioxidant enzymes. The presented thesis summarises actual data about pyrethroids and their influence on fish. The demonstrated effects confirm high susceptibility of early developmental stages of fish to tested pesticides. When interpreting the results, we have to take into account the fact that studies showed this risk even on single pyrethroid substances. But water organisms are exposed to many other more or less toxic products and substances in a real environment. These xenobiotics could react with each other and their mixture could even potentiate negative effects. The performed studies also clearly show the significant differences in the sensitivity of embryonic and embryolarval tests.
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Degradation of pyrethroids using heterogeneous catalysts
Janík, Ondřej ; Bílková, Zuzana (referee) ; Vávrová, Milada (advisor)
This thesis was provided to study fotocatalytic degradation of polutants on the titanium dioxide, as modern eliminating method useful for removing of polutants out of the environmental matrix. There are also studied pyrethroids, as one of the most used pesticides in recent ages, and posibility of degradation of pyrethroids using degradation on titanium dioxide in aquatic system. This study contains an experiment of fotocatalytic degradation of pyrethroids on titanium dioxide in vitro with final analysis using GC-ECD.
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Pyrethroids in abiotic and biotic environmental matrices
Kociánová, Veronika ; Vondráčková, Ilona (referee) ; Vávrová, Milada (advisor)
Synthetic pyrethroids form the main class of synthetic organic insecticides, which are applied in agriculture, household, and public health. Synthetic pyrethroids account form more than 30% of insecticide use worldwide, thereby they gradual replace chemicals of insect pest control as organochlorine and organophosphate insecticides. Pyrethroids are synthetic derivates of natural pyrethrins. In comparison with natural pyrethrins have pyrethroids greater photostability, greater resistence to degradation and greater insecticidal activity. Pyrethroids are labeled as potent neurotoxicants, which interact with sodium channels. Pyrethroids occur in abiotic and biotic environmental matrices. In this study we focused on the determination of this compounds in environmental water samples by GC-ECD, because of the pyrethroids contain atoms of nitrogen and halogens in their structure.
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