Platinum group elements
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Due to limited data-describing abilities of mushrooms to accumulate platinum group elements (PGEs) and rare-earth elements (REEs), the aim of this study was to determine, by inductively coupled plasma optical emission spectrometry followed by microwave-assisted sample digestion by nitric acid, the content of these elements in 20 mushroom species (10 above ground and 10 growing on wood), mostly edible, collected near a busy trunk road. The highest content of PGEs in above-ground mushroom species was observed in Lepista gilva and Suillus bovinus fruit bodies (0.38 ± 0.05 and 0.37 ± 0.03 mg kg(-1) DW, respectively), while in mushrooms growing on wood, the highest content was observed in Pleurotus ostreatus (0.35 ± 0.04 mg kg(-1) DW). The mean content of PGEs for both these groups was 0.23 ± 0.08 and 0.26 ± 0.07 mg kg(-1) DW, respectively. The highest content of REEs in Suillus luteus and Tricholoma equestra was 5.03 ± 0.50 and 2.18 ± 0.56 mg kg(-1) DW, respectively, but within mushrooms growing on wood in Ganoderma applanatum fruiting bodies it was 4.19 ± 0.78 mg kg(-1) DW. Mean contents of REEs were 1.39 ± 1.21 and 1.61 ± 0.97 mg kg(-1) DW in above-ground species and species growing on wood, respectively. Generally, the group of mushroom species growing on wood was capable of slightly higher accumulation of both REEs and PGEs. No limits have been established for both the groups until now.
- MeSH
- Agaricales chemie klasifikace růst a vývoj MeSH
- kovy vzácných zemin analýza MeSH
- platina analýza MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Polsko MeSH
OBJECTIVES: Trace concentrations of the platinum group elements (PGE; Pt, Pd and Rh) are nowadays an irreplaceable part of environmental analysis and assessment. These rare elements are used as effective substances in automotive catalysts to reduce pollution by emissions originating from fuel combustion. Due to their harmful potential, it is necessary to monitor their content and behaviour in different samples. Effect assessment using ecotoxicological bioassays with organisms at different trophic levels can provide valuable pieces of information on the risk of chemical substances in the ecosystem. DESIGN: The experiments were carried out as described in the OECD Guideline 232 [CSN ISO 11267 - Soil quality - Inhibition of reproduction of Collembola (Folsomia candida) by soil pollutants]. The reproductive effects of palladium (PdCl2) and rhodium (RhCl3) were examined. Concentrations of PGE tested were as follows: 5, 10, 25, 50 and 100 µmol.L-1. The EC50 (medium effective concentration) was determined after 28 days of exposure. Inhibition of reproduction of PGE-exposed collembolans was compared against controls. RESULTS: Values of 28dEC50 of PdCl2 and RhCl3 amounted to 21.0 µmol.L-1 and 266.22 µmol.L-1, respectively. We can confirm that the relative order of toxicities is Pd (II) > Pt(IV) > Rh(III). CONCLUSION: To the best of our knowledge, this is the first study to use Folsomia candida as an indicator species to assess the risk of soil contamination by palladium and rhodium. However, more toxicity data for various species are needed to evaluate the environmental risks of PGEs in soils.
- MeSH
- členovci účinky léků fyziologie MeSH
- látky znečišťující půdu analýza toxicita MeSH
- monitorování životního prostředí metody MeSH
- palladium toxicita MeSH
- platina analýza toxicita MeSH
- půda chemie MeSH
- rhodium toxicita MeSH
- rozmnožování účinky léků MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Powdered samples of new and old gasoline catalysts (Pt, Pd, Rh) and new and old diesel (Pt) catalysts were subjected to a pH-static leaching procedure (pH 2-9) coupled with thermodynamic modeling using PHREEQC-3 to verify the release and mobility of PGEs (platinum group elements). PGEs were released under acidic conditions, mostly exhibiting L-shaped leaching patterns: diesel old: 5.47, 0.005, 0.02; diesel new: 68.5, 0.23, 0.11; gasoline old: 0.1, 11.8, 4.79; gasoline new 2.6, 25.2, 35.9 in mg kg(-1) for Pt, Pd and Rh, respectively. Only the new diesel catalyst had a strikingly different leaching pattern with elevated concentrations at pH 4, probably influenced by the dissolution of the catalyst carrier and washcoat. The pH-static experiment coupled with thermodynamic modeling was found to be an effective instrument for understanding the leaching behavior of PGEs under various environmental conditions, and indicated that charged Pt and Rh species may be adsorbed on the negatively charged surface of kaolinite or Mn oxides in the soil system, whereas uncharged Pd and Rh species may remain mobile in soil solutions.
OBJECTIVES: Regarding the environmental pollution, platinum group elements (PGE) are in the centre of interest of current research. These rare elements are used as effective substances in automotive catalysts to reduce pollution by emissions originating from fuel combustion. Due to their harmful potential, it is necessary to monitor their content and behaviour in different samples. Comprehensive studies on PGE behaviour and effects are still lacking. Their distribution in the food chain and data on bioaccumulation has not been described so far. METHODS: We focused on reproductive effects of platinum (PtCl4), in particular. Our study is based on a collembolan laboratory breed, test optimalization and validation according to the OECD 232 standards [CSN ISO 11267 - Soil quality - Inhibition of reproduction of Collembola (Folsomia candida) by soil pollutants]. The concentrations of PtCl4 tested were as follows: 5, 10, 25, 50 and 100 µM. The EC50 was determined after 28 days of testing. RESULTS: The results were evaluated using the inhibition of reproduction compared with controls. The EC50 was determined after the 28-day test. The value of 28dEC50 of the boric acid test was estimated at 120 mg/kg and the measured 28dEC50 of PtCl4 was 200.4 µM. CONCLUSION: The presented data can be considered as a step forward in the assessment of the potential risk of platinum in the terrestrial environment. However, more toxicity data for various species are needed to evaluate the environmental risk of platinum in soils.
- MeSH
- chování zvířat účinky léků MeSH
- členovci účinky léků růst a vývoj MeSH
- látky znečišťující půdu toxicita MeSH
- platina toxicita MeSH
- rozmnožování účinky léků MeSH
- sloučeniny platiny toxicita MeSH
- testy toxicity MeSH
- věkové faktory MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Technology-critical elements (TCEs) include most rare earth elements (REEs), the platinum group elements (PGEs), and Ga, Ge, In, Nb, Ta, Te, and Tl. Despite increasing recognition of their prolific release into the environment, their soil to plant transfer remains largely unknown. This paper provides an approximation of the potential for plant uptake by calculating bioconcentration factors (BCFs), defined as the concentration in edible vegetable tissues relative to that in cultivation soil. Here data were obtained from an indoor cultivation experiment growing lettuce, chard, and carrot on 22 different European urban soils. Values of BCFs were determined from concentrations of TCEs in vegetable samples after digestion with concentrated HNO3, and from concentrations in soil determined after 1) Aqua Regia digestion and, 2) diluted (0.1 M) HNO3 leaching. For comparison, BCFs were also determined for 5 traditional metal contaminants (TMCs; As, Cd, Cu, Pb, and Zn). The main conclusions of the study were that: 1)BCF values for the REEs were consistently low in the studied vegetables;2)the BCFs for Ga and Nb were low as well;3) the BCFs for Tl were high relative to the other measured TCEs and the traditional metal contaminants; and 4) mean BCF values for the investigated TCEs were generally highest in chard and lowest in carrot. These findings provide initial evidence that there are likely to be real and present soil-plant transfer of TCEs, especially in the case of Tl. Improvements in analytical methods and detection limits will allow this to be further investigated in a wider variety of edible plants so that a risk profile may be developed.
OBJECTIVES: An enhanced worldwide application of platinum group elements (PGE), in particular platinum, has been observed during recent decades. An increased concentration of PGE was determined in collected samples of great amount of aqueous ecosystems.The aim was to compare phytotoxic effect of platinum (PtCl4) by performing two different bioassays on green algae Pseudokirchneriella subcapitata and macrophyte duckweed, Lemna minor. MEDTHODS: The algal experiment (Pseudokichneriella subcapitata) followed OECD 201, the concentration row for PtCl4 was: 0.05; 0.01; 0.25; 0.5; 1 μM. The duckweed (Lemna minor) experiment was conducted according to OECD 221, employed PtCl4 concentrations were: 5; 10; 25; 50; 100 μM. Plants were cultivated as a microbiotest, using micro-volumes. RESULTS: The results of the algal test showed significant growth inhibition of the final biomass. The values of 72hEC5(μ), 72hEC10(μ), 72hEC20(μ) counted on a basis of average specific growth rate (μ) were 0.31 μM, 0.58 μM and 1.12 μM of PtCl4, respectively. The values, obtained on a basis of the area under the growth curves (A), were 0.04 μM (72hEC5(A)), 0.24 μM (72hEC10(A)) and 0.64 μM (72hEC20(A)). The experiment with duckweed showed 50% of growth inhibition and the values of 168hEC50(μ) were 19.55 μM and 168hEC50(A) 13.63 μM of PtCl4. CONCLUSION: The fronds of duckweed showed strong adverse effect of platinum influence (chlorosis, necrosis). The algal test and the estimation of 72hEC5(A) appears to be the most sensitive.
- MeSH
- biomasa MeSH
- biotest MeSH
- chemické látky znečišťující vodu toxicita MeSH
- Chlorophyta účinky léků růst a vývoj MeSH
- ekosystém MeSH
- platina toxicita MeSH
- sloučeniny platiny toxicita MeSH
- testy toxicity MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
Powder samples prepared from gasoline (Pt, Pd, Rh, new GN/old GO) and diesel (Pt, new DN/old DO) catalysts and recycled catalyst NIST 2556 were tested using kinetic leaching experiments following 1, 12, 24, 48, 168, 360, 720 and 1440-h interactions with solutions of 20mM citric acid (CA), 20 mM Na(2)P(4)O(7) (NaPyr), 1 g L(-1) NaCl (NaCl), a fulvic acid solution (FA-DOC 50 mg L(-1)) and 20 mM CA at pH 3, 4, 5, 6, 7, 8 and 9. The mobilisation of platinum group elements (PGEs) was fastest in solutions of CA and NaPyr. In the other interactions (NaCl, FA), the release of PGEs was probably followed by immobilisation processes, and the interactions were not found to correspond to the simple release of PGEs into solution. Because of their low concentrations, the individual complexing agents did not have any effect on the speciation of Pd and Pt in the extracts; both metals are present in solution as the complexes Me(OH)(2), Me(OH)(+). Immobilisation can take place through the adsorption of the positively charged hydroxyl complexes or flocculation of fulvic acid, complexing the PGEs on the surface of the extracted catalysts. The calculated normalised bulk released NRi values are similar to the reaction rate highest in the solutions of CA and NaPyr.
