- [Show abstract] [Hide abstract] ABSTRACT: Conventional electrothermal atomic absorption spectrometric (ETAAS) equipment was extensively modified to enable automated in situ electrodeposition. The original autosampler injection Teflon capillary was replaced by a composite Pt/Teflon capillary which served as an anode in the electrodeposition circuit. Incorporation of a peristaltic pump and of a three-way solenoid under computer control into the sample dispenser circuit provided all necessary steps for automated electrodeposition-ETAAS determination. The automated sequence controlled addition of Pd modifier and of the analyte, electrolysis, withdrawal of spent electrolyte, rinsing, drying and atomization. Performance of the system was evaluated by analyzing Pb in 3% m/v NaCl. Optimization using factorial design yielded 3sigma detection limit of 20 pg Pb and reproducibility of 1.0-1.4% (for constant current electrodeposition), these values being superior to the results of conventional ETAAS of Pb in 0.5% m/v NaCl. Sensitivity of Pb determination is not affected by NaCl, NaOH, NaNO3 and NH4H2PO4, up to 4.6% m/v, demonstrating efficient matrix removal in the electrodeposition step.
- [Show abstract] [Hide abstract] ABSTRACT: The ability of fungi to accumulate metals is a known phenomenon that is studied from both the industrial and ecological point of views. The biosorption and removal of various cations could be useful in recovery of precious or strategic metals as well as in the removal of toxic heavy metals from contaminated water. The most frequently used group of organisms are filamentous fungi, which are widely used in fermentation industries to produce varied metabilites. The application of mycelial wastes as adsorbents or ion-exchangers for the removal of heavy metals represent a possibility for further utilization of these biotechnological by-products. So far, little attention has been paid to interactions of heavy metals with higher fungi. Most of the work deals with metal translocation and uptake from various substrates or with the heavy metal content in fruiting bodies collected in different areas. In several cases this content seems to reflect the concentrations of atmospheric heavy metal. This study looks at both the biosorption of aluminum, cadmium, copper, lead and zinc in native fungal pellets of a wood-rotting basidiomycete and the stress response of the fugus to high concentrations of cadmium ions. 14 refs., 4 figs., 1 tab.
Academy of Sciences of the Czech Republic
Praha, Hlavni mesto Praha, Czech Republic
- Hydrobiologický ústav