Zdenek Simek

• Masaryk University

Understanding how many mates an animal has in its lifetime is a critical factor in sexual selection. At the same time, differences in an organism's ecology, such as the quantity and quality of food, could be reflected in different mating rates. Mating rate had a significant effect on female net fitness (i.e., lifetime offspring production), however...

Understanding how many mates an animal has in its lifetime is a critical factor in sexual selection. At the same time, differences in an organism's ecology, such as the quantity and quality of food, could be reflected in different mating rates. Mating rate is thus an important measure, also on a population level, however, laboratory measurements ca...

Zayandeh Rood river is the most important river in central Iran supplying water for a variety of uses including drinking water for approximately three million inhabitants. The study aimed to investigate the quality of water concerning the presence of pharmaceutical active compounds (PhACs) and hormonelike compounds, which have been only poorly stud...

Determining the age of free-living insects, particularly of blood-sucking species, is important for human health because such knowledge critically influences the estimates of biting frequency and vectoring ability. Genetic age determination is currently not available. Pteridines gradually accumulate in the eyes of insects and their concentrations i...

Enantioselectivity (defined as the enantiomer fraction, EF) in sorption, dissipation and bioaccumulation was assessed for the model compound tebuconazole. Tebuconazole sorption in soils was affected by organic carbon (OC) and clay contents and cation exchange capacity, and appeared to be non-enantioselective for both tested soils, soil components a...

Twenty juvenile individuals of brown bullhead (Ameiurus nebulosus), average weight 77 g, were fed by abiraterone acetate prodrug dissolved in olive oil via gastric probe. Dose applied was 3 mg/10 g fish weight. After feeding, they were let out into aquarium and kept there for 3 days. Aquarium water containing excreted metabolites was extracted, and...

Methods useful for the extraction of alkylphenols from soil samples were assessed. A comparison is made of the four extraction techniques that are most commonly used to extract phenolic compounds from soil, such as bisphenol A, bisphenol F and alkylphenols (4-t-OP, iso-NP, 4-OP and 4-n-NP). Soxhlet extraction, ultrasonic-assisted extraction (USE),...

In birds, concentrations of testosterone (T) and corticosterone (Cort) are closely connected with many morphological, behavioral, and other physiological traits, including reproduction, metabolism, immunity, and fitness. The direction of the effect of these hormones on above‐mentioned traits, and the potential feedback between hormones are in gener...

In birds, concentrations of testosterone (T) and corticosterone (Cort) are closely connected with many morphological, behavioral, and other physiological traits, including reproduction, metabolism, immunity, and fitness. The direction of the effect of these hormones on above‐mentioned traits, and the potential feedback between hormones are in gener...

Analysis of brown bullhead (Ameiurus nebulosus) bile by ultra performance liquid chromatography high-resolution mass spectrometry (UPLC/HRMS) revealed a series of bile acids similar to those found in humans. Accordingly, we chose this fish as a model organism to examine the metabolism of obeticholic acid, a bile acid used to treat a number of human...

Feathers gradually accumulate hormones and reflect long-term average plasma steroid levels during their growth. Feather hormone levels thus provide for the measurement of plasma hormones concentrations integrated over a period of several days or weeks. In this study, we focused on the development of a method to determine testosterone (TEST) and cor...

Environmental context Nanopesticides are increasingly being developed for agricultural use, but knowledge concerning their environmental fate and effects is limited. This microcosm study brings new results about soil fate and bioaccumulation of polymeric or lipid nanoparticles carrying chlorpyrifos or tebuconazole. The nanoformulations significantl...

Epoxiconazole, tebuconazole, flusilazole, prochloraz, pendimethalin, and the atrazine transformation product (2-hydroxyatrazine) have been found in Czech arable soils at high detection frequencies and/or concentrations. As they have been shown to persist from one growing season to following ones, the question arises of whether they can be taken up...

Stagnant water bodies have generally received little attention regarding the presence of endocrine disruptive compounds, although they can integrate diverse pollutants from multiple different sources. Many compounds of anthropogenic as well as natural origin can contribute to the overall estrogenicity of surface waters and some of them can exhibit...

Although large amounts of pesticides are used annually and a majority enters the soil to form short- or long-term residues, extensive soil surveys for currently used pesticides (CUPs) are scarce. To determine the status of CUPs' occurrence in arable land in Central Europe, 51 CUPs and 9 transformation products (TPs) were analysed in 75 arable soils...

In situ extraction of steroid hormones from waste water using adsorption-based integrative passive samplers represents a promising approach for their monitoring in water at ultra-trace concentrations. Three passive samplers, namely a POCIS, a Chemcatcher fitted with an Empore SDB-RPS disk, and an Empore SDB-RPS disk-based sampler with enhanced wate...

Chlorotriazine herbicides (CTs) are widely used pest control chemicals. In contrast to groundwater contamination, little attention has been given to the circumstances of residue formation of parent compounds and transformation products in soils.

The comparison of four extraction techniques for isolation of five native and one labelled steroid oestrogens from sediment was described. The three conventional extraction techniques Soxhlet warm extraction (SWE), accelerated solvent extraction (ASE), microwave-assisted extraction (MAE) and a promising technique QuEChERS were tested for isolation...

Rehabilitation of aged drinking water pipes is an extensive renovation and increasingly topical in many European cities. Spray-on-lining of drinking water pipes is an alternative cost-effective rehabilitation technology in which the insides of pipes are relined with organic polymer. A commonly used polymer is epoxy resin consisting of monomer bisph...

Platform presentation

The present study describes an effect of reaction condition of pre-column derivatization of alkylphenols (APs): bisphenol A (BPA), 4-tert-octylphenol (4-t-OP), 4-octylphenol (4-OP), 4-n-nonylphenol (4-n-NP), and isomers of 4-nonylphenol (iso-NP) with 5-(dimethylamino) naphthalene-1-sulfonyl chloride (dansyl chloride, DNSC) on their LC-ESI-MS/MS det...

Irradiation of N-protected p-hydroxyphenacyl (pHP) ammonium caged derivatives at 313 nm releases primary and secondary amines or ammonia in nearly quantitative yields via the photo-Favorskii reaction when conducted in acidic or neutral aqueous buffered media. The reaction efficiencies are strongly dependent on the pH with the most efficient and hig...

Recently, increasing attention is being paid to the presence of estrogens (female sex hormones) in the environment, especially in aquatic ecosystem. Their occurrence in drinking water is also disturbing because it can have consequences to human health. Various pieces of information, not always comparable, can be found in a literature according to e...

A comparison of four extraction techniques used for the isolation of 14 explosive compounds (Method 8330-Explosives) from spiked soil samples is described. Soxhlet warm extraction (SWE), pressurized solvent extraction (PSE), microwave assisted extraction (MAE) and supercritical fluid extraction (SFE) were included. The effects of basic extraction c...

A new method for the analysis of azaarenes and their degradation products (azaarones) was developed, optimized and validated using liquid chromatography coupled with atmospheric pressure photo ionization tandem mass spectrometric detection (LC-APPI/MS/MS). Seventeen compounds including 4 PAHs (naphthalene, anthracene, phenanthrene, benz[a]anthracen...

The possibility and the efficiency of solid-phase microextraction (SPME) for determination of distribution coefficients of polycyclic aromatic nitrogen heterocycles (PANHs) in aqueous samples are presented in this study. Influence of sample extraction conditions, extraction time, stirring rate, pH, salinity and temperature were tested to optimize e...

The aim of this study was to compare the toxic effects of selected two- and three-ringed PAHs (naphthalene, phenanthrene, and anthracene) and their N-heterocyclic analogs with one (quinoline, acridine, and phenanthridine) or two (quinoxaline, phenazine, and 1,10-phenanthroline) nitrogen atoms on the survival and reproduction of Enchytraeus crypticu...

Microcystins are cyclic peptide toxins with hepatotoxic and tumour-promoting properties which are produced in high quantities in freshwater cyanobacterial water blooms, and several studies have reported microcystin accumulation in fish with possible food transfer to humans. In this study, we provide the first comparison of liquid chromatography wit...

In the environs of ammunition plants and former military area, contaminations caused by explosives and their degradation products are of great environmental relevance. During the production of worldwide mostly used explosive compound – 2,4,6-trinitrotoluene its isomers were distributed into the environment. Therefore determination of 14 selected ni...

The aim of the study was to determine changes of enantiomeric fraction (EF) of chiral compounds interacting with components of soil and to describe the effect of amount of soil components on EF value.Soil components (humic acid and ash) were isolated from soil using method recommended by the International Humic Substance Society (IHSS). Dichloromet...

The separation of a mixture of trinitrotoluenes (TNTs) and their metabolites by reverse phase liquid chromatography using different columns with octadecyl stationary phase is presented. The retention behaviour of a mixture of TNTs and their metabolites was studied under different chromatographic conditions. The mixture of methanol/water was used as...

Cylindrospermopsin (CYN) is a newly emerging carcinogenic alkaloid originally identified in tropical cyanobacteria Cylindrospermopsis raciborskii. Some recent studies reported production of this toxin also by other cyanobacteria in European countries. Here we report comparison of the immunochemical ELISA determination with the liquid chromatography...

Development of LC/MS/MS method for analysing polycyclic aromatic nitrogen heterocycles (PANHs) in soil samples is presented. Optimisation of individual chromatographic/mass spectrometric conditions was made in order to obtain a method for the determination of 15 PANHs content in an organic extract from the soil. Detection limits (LOD) in the range...

The aim of this paper was to measure the changing desorbable fraction and bioaccessibility of phenanthrene in two different soils with increasing soil-phenanthrene contact time using supercritical fluid extractions (SFE). Both soils were spiked with 100 mg kg(-1) phenanthrene and aged for 28d. Desorption profiles were measured every 7d using select...

The study of the separation of polycyclic aromatic nitrogen heterocycles (PANHs) by reverse-phase liquid chromatography with an octadecyl stationary phase is presented. The retention behaviour of a mixture of PANHs was studied under different chromatographic conditions. A mixture of phosphate buffer/acetonitrile was used as mobile phase in isocrati...

Extraction recovery of 10 selected polycyclic aromatic nitrogen heterocycles (PANHs), quinoline, 2-methylquinoline, 6-methylquinoline, 8-methylquinoline, acridine, benzo[h]quinoline, phenantridine, indole, 2-methylindole, and carbazole from spiked soil samples was tested. Four different extraction techniques, pressurized solvent extraction (PSE), s...

This study was focused on the fractionation of the mixture of polycyclic aromatic hydrocarbons and their derivatives, especially nitrated derivatives, found in soil and roadside dust extracts. Liquid chromatography with an open silica gel bed was used. Different volumes of hexane, hexane:dichloromethane (1:1 and 4:1, v/v), dichloromethane and metha...

Kinetics of photodegradation, half lifes and photodegradation products of two parent polycyclic aromatic hydrocarbons (anthracene and chrysene), their methyl-derivatives (9-methylanthracene and 6-methylchrysene) and selected nitro-derivatives (9-nitroanthracene and 6-nitrochrysene) were observed during exposition to UV irradiation in isooctane solu...

An analytical method based upon the pressurised solvent extraction and gas chromatography and mass spectrometry (GC-MS) for analysis of nitrated derivatives of polycyclic aromatic hydrocarbons (nitro-PAHs) in roadside dust has been developed. Five nitro-PAHs (1-nitronaphthalene, 1-nitropyrene, 9-nitroanthracene, 2-nitrofluorene, 6-nitrochrysene) we...

The possibilities of utilising pressurised liquid extraction for five nitro-polycyclic aromatic hydrocarbons from an inert matrix are shown. Different extraction temperatures and pressures were tested. The highest recoveries were obtained at extraction pressure 14 MPa and temperature 100 C. Separation of non-polar, aromatic and polar fractions by t...

The complexation equilibria of Ni(II) with 4-(2-pyridylazo)resorcinol (PAR) and 4-(2-thiazolylazo)resorcinol (TAR) in 30 vol.% ethanol and with 2-(5-bromo-2-pyridylazo)-5-(diethylamino)phenol (BrPADAP) in 10 vol.% ethanol containing 0·1% BRIJ-35 tenside were studied spectrophotometrically. The absorbance data were processed by the SPEFO 8, HALTAFAL...