Jürgen Messerschmidt

First report on the uptake of automobile catalyst emitted palladium by European eels (Anguilla anguilla) following experimental exposure to road dust

Following the introduction of automobile catalysts in the middle of the 1980s in Germany there is an increasing emission of the platinum-group-metals platinum, palladium (Pd) and rhodium. Still, it remains unclear if these metals are bioavailable for aquatic animals and to which extent they become accumulated by the aquatic biosphere. Because of analytical problems in detecting Pd in small biological samples the present investigation concentrates on the bioavailability of this metal. To answer the question of a Pd uptake by aquatic organisms experimental studies were conducted with European eels maintained in water containing road dust at a concentration of 10 kg/100 l. Following an exposure period of four weeks, samples of liver and kidney were analysed by total-reflection X-ray fluorescence analysis after co-precipitation of Pd with mercury. These experiments revealed an uptake of traffic related Pd by European eels which showed a mean liver Pd concentration of 0.18 +/- 0.05 ng/g (wet wt.), whereas the Pd concentration in the kidney ranged below the detection limit. Thus, in this study we can demonstrate for the first time that automobile catalyst emitted Pd is bioavailable for aquatic animals.

Circulating plasma platinum more than 10 years after cisplatin treatment for testicular cancer

We have shown in patients cured from metastatic testicular cancer that up to 20 years after administration of cisplatin-containing chemotherapy, circulating platinum is still detectable in plasma. This finding may influence the development of long-term, treatment-related side-effects.

Separation and enrichment of palladium and gold in biological and environmental samples, adapted to the determination by total reflection X-ray fluorescence

The reductive co-precipitation of trace and ultra-trace elements together with mercury followed by complete evaporation of the mercury makes it possible to determine palladium and gold by total reflection X-ray fluorescence. Both elements can be detected without interferences at optimal sensitivity in the pg range. Thus, detection limits of, e.g., 2.5 ng L-1 for palladium and 2.0 ng L-1 for gold, in urine, were obtained. The precision was determined to 0.04 at a palladium concentration of about 200 ng L-1 urine and to 0.19 at a gold concentration of only 18 ng L-1. The recovery for a urine sample spiked with known amounts of palladium and gold amounted to > 95%. Results of the combined procedure are given for the determination of palladium and gold in the urine of non-exposed and occupationally exposed persons and in some other environmentally relevant samples.

Relevance and analysis of traffic related platinum group metals (Pt, Pd, Rh) in the aquatic biosphere, with emphasis on palladium.

Following the introduction of automobile catalysts in the middle of the Eighties in Germany there is an increasing emission of the platinum-group-metals (PGM) platinum (Pt), palladium (Pd) and rhodium (Rh). Still, it remains unclear if these metals are bioavailable for aquatic animals and to which extent they accumulate in the aquatic biosphere. Zebra mussels (Dreissena polymorpha ) were maintained in water containing road dust at a concentration of 1 kg/10 l. Following an exposure period of 26 weeks, soft tissues of the mussels were analysed applying adsorptive cathodic stripping voltammetry (ACSV) for the determination of Pt and Rh and total-reflection X-ray fluorescence analysis after co-precipitation of Pd with mercury. This experiment revealed for the first time that all the three catalyst emitted metals were accumulated by mussels. The bioaccumulation increased in the following manner: Rh<Pt<Pd. Thus, the application of sentinel organisms in combination with modern trace analytical procedures in environmental impact studies does allow an assessment of the distribution and the degree of bioaccumulation of PGM in the environment, which is highly appreciated.

Platinum species analysis in plant material by gel permeation chromatography

Abstract Model experiments for the analysis of platinum species in extracts from native and platinum treated grass cultivation are described. The procedural steps are cultivation of the grass samples, preparative separation of the Pt species and analytical detection and characterisation of the separated species. The platinum uptake from the roots resulted by treating the grass cultivation with an aqueous solution of tetrammineplatinum(II) nitrate, [Pt(NH 3 ) 4 ](NO 3 ) 2 . The grass was cut, the cell fluid extracted and the Pt species were separated by gel permeation chromatography. The extremely sensitive adsorptive voltammetry was used for the sequential determination of platinum in the elution fractions. The estimation and determination of the molecular weights were carried out by gel permeation and liquid chromatography. In the native grass extract only one Pt species (160–200 kD) was detected. In the platinum treated grass extracts several Pt species were observed. More than 90% of all the platinum is bound to a low molecular weight species (about 1 kD), whereas less than 10% of the platinum is bound to species with molecular weights from 19 up to > 1000 kD.

Speciation of platinum metabolites in plants by size-exclusion chromatography and inductively coupled plasma mass spectrometry

The multi-element capability of ICP-MS was exploited in a study of platinum metabolization in plants. Grass was cultivated with and without treatment with a Pt containing solution. Platinum species were extracted and separated by ultrafiltration into two mass fractions. The low molecular mass (<10 kDa) fraction was investigated by size-exclusion chromatography coupled on-line to ICP-MS. Five Pt containing fractions could be distinguished in the chromatograms. Conclusions on the binding partners of Pt could be drawn from multi-element determinations of some selected elements (C, S, Ca, Pb) that are co-eluted with Pt. For two of them (S, Ca), the higher mass resolution available with a double focusing magnetic field ICP-MS instrument was applied in order to cope with problems from spectroscopic interferences.

The determination of platinum in biotic and environmental materials. I: μg/kg- to g/kg-range

A simple and reliable procedure for the determination of platinum including high pressure ashing, separation and detection by graphite furnace AAS has been developed. It was put to practical use in the analysis of biotic and environmental materials polluted with platinum in the concentration rangeμg/kg to g/kg.

Adsorptive voltametry to determine platinum levels in plasma from testicular cancer patients treated with cisplatin.

Patients cured of metastatic testicular cancer with cisplatin chemotherapy may suffer late adverse effects even after 20 years. The cause of these late adverse effects has not been elucidated yet. One cause might be prolonged tissue retention of platinum in these patients. Therefore, an extremely sensitive method for measuring platinum in plasma was used to investigate whether platinum is still detectable in plasma 10 to 20 years after cisplatin chemotherapy. High-pressure decomposition of plasma is followed by adsorptive voltametric determination of platinum, with a limit of quantification of 6 pg/g plasma. This procedure appeared suitable for the measurement of platinum in 44 former patients with platinum levels ranging from 22 to 140 pg/g plasma. This method is approximately 6000 times more sensitive than the standard flameless atomic absorption spectrophotometry (AAS) method. The platinum levels of these 44 patients were significantly elevated when compared with 20 control patients who were cured of testicular cancer but did not receive cisplatin chemotherapy (p < 0.001). There was a significant correlation between plasma platinum concentrations and follow-up time after cisplatin administration (r = −0.658 , p < 0.001). This study shows that patients with testicular cancer who were treated with cisplatin can retain platinum in their body for at least 20 years. More data are needed to investigate whether there is a relation between the prolonged retention of platinum and long-term toxicity.

Investigation of low molecular weight platinum species in grass

The analysis of the low molecular weight fraction (<10 kDa) of platinum species in grass is described. This fraction is isolated by ultrafiltration, gel-chromatography and preparative isotachophoresis and then further separated by liquid chromatography with diode-array UV and pulsed amperometric detection. Platinum is determined in eluted fractions by using a very sensitive adsorptive voltammetric method. The strong correlation of platinum concentration with the highly selective pulsed amperometric detection enables the platinum binding ligands to be identified as carbohydrate-oligomers (MW about 1 kDa). Further evidence of this result is obtained by using capillary electrophoresis as an independent separation technique.

Accumulation of the precious metals platinum, palladium and rhodium from automobile catalytic converters in Paratenuisentis ambiguus as compared with its fish host, Anguilla anguilla

The platinum group metals (PGM) Pt, Pd and Rh are emitted into the environment mainly by catalytic exhaust gas converters of cars. As PGM accumulate in sediments of aquatic ecosystems, the study was focused on the uptake of the noble metals by European eels, Anguilla anguilla infected with the acanthocephalan Paratenuisentis ambiguus. Eels were exposed to ground catalytic converter material for six weeks. After exposure Pt and Pd were detected in the liver and kidney of the eels and in the parasites. Palladium was also found in fish muscle and intestine. No Rh uptake by the eel tissues and the parasites occurred. Paratenuisentis ambiguus contained the highest levels of both metals with 40 times higher Pt concentrations and four times higher Pd concentrations than the liver of its host. Due to its accumulation capacity for PGM, P. ambiguus can be applied as a sensitive accumulation indicator in field studies to assess the degree of environmental PGM contamination in aquatic ecosystems.