Fractionation of traffic-emitted Ce, La and Zr in road dusts.

The introduction of catalytic converters has led to a new environmental problem since catalysts emit platinum group elements (PGEs) which are among the least distributed elements in nature. Along with PGEs the vehicle exhaust catalysts contain also a number of stabilizers, commonly oxides of rare earth elements and alkaline earth elements such as Ce, La and Zr. Since vehicular emission of these elements has received little attention so far this work attempts to offer insight into their distribution and fate in the environment by measuring their speciation in road dust samples collected along several highways in Germany and a city centre (Saarbrücken). Speciation of the elements (fractionation into associated mineralogical phases) was carried out via a conventional sequential extraction protocol and the complexing abilities of humic substances in the organic matter were investigated by selective extraction methods in combination with size segregation. For evaluation purposes soil samples spiked with catalytic converter material were analyzed, showing a much lower fraction of Ce, La and Zr mobilized in comparison to the road dust samples. It was found that the elements were effectively bound to humic substances in road dust with a preference for complexation with low molecular weight compounds (<1600 Da).

Recycling of 18O enriched water used in 18F cyclotron production.

A simple, effective, easy-handling and reliable method for recycling of [18O]H2O from fluorine-18 production, was developed based on co-precipitation, co-crystallization and distillation. Preliminary experiments with normal H2O were used to determine the optimal purification conditions, which were tested for purification of used [18O]H2O from a scientific and commercial 18F-production facility. The obtained recycled [18O]H2O had comparable quality to commercially available 18O enriched water. The loss of weight for enriched water was about only 7% and losses of 18O enrichment about 1.3% ±â€¯0.2%. The method ensures elimination of radioisotopes (99.7% ±â€¯0.1%), organic compounds (99.5% ±â€¯0.1%) and trace metals (99.8% ±â€¯0.1%) with special attention on radiation safety with dosimetry control checks and in total 1000 times mass reduction of the initial radioactive waste.

HPLC-HRMS method for fast phytochelatins determination in plants. Application to analysis of Clinopodium vulgare L.

An optimized analytical method based on C8 core-shell reverse phase chromatographic separation and high resolution mass spectral (HRMS) detection is developed for a fast analysis of unbound phytochelatins (PCs) in plants. Its application to analysis of Clinopodium vulgare L. is demonstrated where proper PCs liberating and preservation conditions were employed using dithiotreitol in the extraction step. A baseline separation of glutathione (GSH) and phytochelatins from 2 to 5 (PC2-PC5) for 3 min was achieved at conventional HPLC backpressure, with detection limits from 3 ppt (for GSH) to 2.5 ppb (for PC5). It is shown, that the use of HRMS with tandem mass spectral (MS/MS) capabilities permits additional wide range screening ability for iso-phytochelatins and PC similar compounds, based on exact mass and fragment spectra in a post acquisition manner.

Speciation of inorganic platinum-chloride complexes in spiked environmental samples by SPE and ICP-AES.

A method for the separation of tetrachloroplatinate PtCl(4)(2-), and hexachloroplatinate PtCl(6)(2-), by solid-phase extraction, using a Dowex 1x10 anion exchange resin is proposed. The sequential elution and separation of PtCl(4)(2-), and PtCl(6)(2-) is achieved using selective complexing agents. The eluates, containing Pt(II) and Pt(IV) were analyzed by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Recoveries of 102% for PtCl(4)(2-) and 94% for PtCl(6)(2-) and detection limit of 15 ng g(-1) were achieved. Using this method determination of Pt(II) and Pt(IV) in soil samples, spiked with different platinum species was performed. The comparison with GFAAS determination showed a very good agreement.