Platinum, palladium, and rhodium deposition to the Prunus laurus cerasus leaf surface as an indicator of the vehicular traffic pollution in the city of Varese area: an easy and reliable method to detect PGEs released from automobile catalytic converters.
ABSTRACT The widespread use of some platinum group elements as catalysts to minimize emission of pollutants from combustion engines produced a constantly growing increase of the concentration of these elements in the environment; their potential toxicological properties explain the increasing interest in routine easy monitoring. We have found that leaves of Prunus laurus cerasus are efficient collectors of particulate with a dimension <60-80 mum, and a simple and reliable procedure was developed to reveal traces of platinum, palladium, and rhodium released from automotive catalysts. The analysis of the dust deposited on the foliage is a direct indicator of traffic pollution.
Leaves of P. laurus cerasus were washed by sonication in a mixture of water and 2-propanol and the washings, to be discarded, were separated by centrifugation to yield typically 0.05-1.2 g of dust that, after mineralization, was directly submitted for atomic absorption analysis.
Comparison of the 2007 and 2004-2005 results showed a dramatic reduction of the platinum levels and revealed that palladium is now the main component of this traffic-related pollution.
The results are consistent with the increasing diffusion of cars with a diesel engine whose catalysts are made up of Pt and/or Pd alone, and gives a significant insight into the recent evolution in catalyst design that replaces platinum for palladium.
The proposed analytical procedure is simple, with short preparation times, and greatly reduces matrix effects so that atomic absorption spectroscopy can easily detect the three noble metals at the ng/g level in the dust.
The results clearly show that Pd concentrations have increased over time, and must be cause for concern.
- Toxic Effects of Nanomaterials, Edited by Haseeb Ahmad Khan, Ibrahim Abdulwahid Arif, 01/2012: chapter Nanoparticle-Induced Toxicity: Focus on Plants: pages 3-27; Bentham Science., ISBN: 978-1-60805-283-7
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ABSTRACT: Automobile catalysts are major anthropogenic sources of ultra-traces of platinum group elements (PGEs) in the environment. Nanoparticles of platinum, palladium, and rhodium, the active components of autocatalysts, are being spread into the environment during vehicle operation. Bioaccumulation of the metals can lead to their elevated levels in living organisms. The evaluation of the health risk from PGEs requires the investigation of a large variety of environmental and biological materials for their content. Plants, airborne particulate matters, soils, and sediments are most often examined for such purposes. The introduction of platinum and ruthenium complexes as anticancer agents into chemotherapy has stimulated growing interest in their determination in clinical materials (physiological fluids and tissues). Identification and determination of drug species formed under physiological conditions are fundamental for recognition of the mechanism of their biological activity. Analytical procedures applicable to the determination of PGEs in various environmental and clinical samples are reviewed in this article.Critical Reviews in Analytical Chemistry 07/2011; 41(3):214-235. · 2.69 Impact Factor
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ABSTRACT: Conventional approaches for the analysis of platinumgroup elements (PGEs) in plantmaterial suffer fromsample digestionwhich results in sample dilution and therefore requires high sample intakes to maintain the sensitivity. The presented solid-sampling method avoids sample digestion while improving sensitivity when compared to digestion-based inductively coupled plasma optical emission spectrometry (ICP-OES) methods and allows the analysis of sample masses of 5 mg or less. Detection limits of 0.38 μg g−1, 0.14 μg g−1 and 0.13 μg g−1 were obtained for Pt, Pd and Rh, respectively using a sample intake of 5 mg. The reproducibility of the procedure ranged between 4.7% (Pd) relative standard deviation (RSD, n = 7) and 7.1% (Rh) RSD for 25 ng analytes. For quantification, aqueous standards were applied on paper filter strips and dried. Only the dried filters were introduced into the electrothermal vaporization unit. This approach successfully removed memory-effects observed during analysis of platinumwhich occurred only if liquid standards came into contactwith the graphite material of the furnace. The presented method for overcoming the Pt-memory-effects may be of further interest for the analysis of other carbide-forming analytes as it does not require any technical modification of the graphite furnace (e.g., metal inlays, pyrolytic coating). Owing to lack of suitable certified reference materials, the proposed method was compared with conventional ICP-OES analysis of digested samples and a good agreement was obtained. As a result of the low sample consumption, it was possible to determine the spatial distribution of PGEs within a single plant. Significant differences in PGE concentrations were observed between the shoots (stem, leaves) and the roots. Pd was mainly found in the roots, whereas Pt and Rh were also found in higher concentrations in the shoots.Spectrochimica Acta Part B Atomic Spectroscopy 10/2013; 89:60-65. · 3.15 Impact Factor