ABSTRACT
The determination of polychlorinated biphenyls (PCBs) in water, sediment and fish samples from the Czech Republic was carried out using high resolution gas chromatography with electron capture detection. PCBs concentrations in water and sediment samples were rather low and corresponded with the findings from some prior studies. On the other hand, investigated samples of fish tissue were highly contaminated (on average 1.3-266 ng/g fat for individual PCBs), thus, a continuing contamination of fish species with PCBs was proved.
Subject(s)
Environmental Monitoring , Environmental Pollutants/analysis , Polychlorinated Biphenyls/analysis , Adipose Tissue/chemistry , Animals , Chromatography, Gas , Cyprinidae , Czech Republic , Geologic Sediments/chemistry , Water/chemistryABSTRACT
Flexible biodegradable polyurethane foams (BIO-PUR) were prepared by a one-shot process using commercially available coreactants and modified by substituting biodegradable additive based on the acetylated starch (AS), acetylcellulose (AC), 2-hydroxyethylcellulose (HEC) and carboxymethylcellulose sodium salt (CMC) for 5 or 10 wt% of commercial polyether polyol. The BIO-PUR foams were characterized by FTIR, TGA and polarization microscopy. Ecotoxicity of BIO-PUR foams freshwater extracts was evaluated using the alternative crustacean toxicity test Thamnotoxkit F. Values of toxicity were expressed as percentage mortality of the instars II-III larvae of freshwater fairy shrimps (Thamnocephalus platyurus) dependence on the effect criterion of the respective assay. The leaches of BIO-PUR foams modified with 5 or 10 wt% of HEC showed higher toxicity then other BIO-PUR foams, whereas leaches of BIO-PUR with 5wt% of AS and 10wt% of AC were even less toxic than REF. PUR foam.
Subject(s)
Environmental Pollutants/chemistry , Environmental Pollutants/toxicity , Polyurethanes/chemistry , Polyurethanes/toxicity , Animals , Anostraca/drug effects , Anostraca/physiology , Biodegradation, Environmental , Larva/drug effects , Materials Testing , Microspheres , Spectroscopy, Fourier Transform Infrared , Time Factors , Toxicity Tests, AcuteABSTRACT
Flubendazol is a veterinary antiparasitic agent which acts toxically on both adult and larval stages of round worms. It is nearly insoluble in water and it influences not only the selection of the dosage form, but also its biological availability. Its solubility can be increased by adding solutizers and tensides, or by complex-formation with cyclodextrins. In the published experimental paper the method of complex-formation of flubendazol with 2-hydroxypropyl-beta-cyclodextrin was employed and the effect of temperature on the resultant solubility of the active ingredient was examined. The final dosage form was pellets produced with the use of the method of extrusion and spheronisation.
Subject(s)
Antinematodal Agents/chemistry , Cyclodextrins/chemistry , Mebendazole/analogs & derivatives , Mebendazole/chemistry , Pharmaceutic Aids , Solubility , Temperature , beta-Cyclodextrins , 2-Hydroxypropyl-beta-cyclodextrin , Chemistry, PharmaceuticalABSTRACT
A method for quantitative determination of iodide in milk by use of the ion-selective electrode is described. The proposed method is rapid and simple. No sample pretreatment is required exept for sample ionic strength adjustment. It was possible to determine iodide concentrations down to 40 microgram/l with average relative standard deviation of 3,4%. The concentration of iodide in milk samples determined by this method ranged from 61,5 microgram J-/l to 190,8 microgram J-/l.
