Exposure of the German general population to platinum and rhodium - Urinary levels and determining factors.

In this study the exposure of the general population in Germany to platinum and rhodium and its determinants was investigated in 259 participants (subdivided in three groups) by urine analyses and assessment of the dental status. Complementary, an interview including questions characterising possible exposure to traffic exhaust was conducted. The median excretion was 2.42ng platinum/g creatinine and 7.27ng rhodium/g creatinine. The detailed analysis of the collected data showed significant higher platinum excretion values with increasing number of surfaces covered with restorations containing precious metals (R=0.389; p<0.001), but also higher values for habitants of urban areas (median=3.43ng/g creatinine; 95th percentile=25.2ng/g) compared with those of rural areas (median=2.06ng/g creatinine; 95th percentile=20.0ng/g). Also, participants working in urban areas showed higher platinum excretion values (median=3.27ng/g; 95th percentile=19.6ng/g). Male participants living and working next to highly frequented roads showed higher rhodium excretion values (median=7.27ng/g; 95th percentile=13.5 ng/g). In summary, the study showed that exhaust emissions have an influence on platinum and rhodium excretion, but for platinum this influence is rather low compared to the influence of precious metals containing restorations.

Determination of Rh, Pd and Pt in urine samples using a pre-concentration sequential injection analysis system coupled to a quadrupole-inductively coupled plasma-mass spectrometer.

The proposed flow system was developed in order to minimize the drawbacks related to the PGEs determination by quadrupole-inductively coupled plasma-mass spectrometry (Q-ICP-MS). It was intended not only to lower the limits of detection (LODs) but also to eliminate the interferences originating from some atomic and molecular ions produced in the argon plasma. This was accomplished by means of an on-line sample clean-up/pre-concentration step, using a chelating resin (Metalfixtrade mark Chelaminetrade mark) in which Rh, Pd and Pt were preferably retained when compared with the interfering species. The results obtained by using the developed flow system in the analysis of urine samples are presented. With a sampling rate of 9 samples h(-1) (i.e., 27 determinations) and a sample consumption of ca. 10 mL, the developed flow system allowed linear calibration plots up to 100 ngL(-1) with detection limits of 1.2 ngL(-1) (Rh), 0.4 ngL(-1) (Pd) and 0.9 ngL(-1) (Pt). Repeatability studies showed good precision (R.S.D.%, n=5): 3.7% (Rh); 2.6% (Pd) and 2.4% (Pt), for 10 ngL(-1); 2.4% (Rh); 1.4% (Pd) and 1.9% (Pt), for 50 ngL(-1); and 1.3% (Rh); 0.58% (Pd) and 0.62% (Pt), for 100 ngL(-1). By spiking human urine samples, recovery tests were performed, and the values obtained ranged between 89% and 105% (Rh); 90% and 104% (Pd); and 93% and 105% (Pt).

Biomonitoring of tram drivers exposed to airborne platinum, rhodium and palladium.

OBJECT: The aim of this study was to evaluate urinary levels of Pt, Rh and Pd in occupationally exposed subjects. METHODS: A total of 122 healthy male subjects of Rome (Italy) were studied; 64 were municipal tram drivers and 58 control subjects. Metal quantification in the urine samples was carried out by sector field inductively coupled plasma mass spectrometry. RESULTS: There were statistically significant differences between urinary Pt and Rh levels of the workers and the control group (Pt median: 1.23 versus 1.03 ng/g creatinine; Rh median: 19.16 versus 11.18 ng/g creatinine), while no difference in Pd levels was observed (Pd median: 11.47 versus 8.75 ng/g creatinine). CONCLUSIONS: Urinary Pt and Rh could be useful biomarkers for monitoring population groups occupationally exposed to these elements. Urinary concentration of Pt and Rh, though still low, could be of some concern in workers heavily exposed to urban car traffic.

Simultaneous determination of palladium, platinum and rhodium by on-line column enrichment and HPLC with 5-(2,4-dihydroxyphenylazo)-rhodanine as pre-column derivatization reagent.

In this paper, a new method for the simultaneous determination of palladium, platinum and rhodium ions was developed using a rapid column high performance liquid chromatography equipped with on-line enrichment technique. The palladium, platinum and rhodium ions were pre-column derivatized with DHAR to form colored chelates. The Pb-DHAR, Pt-DHAR and Rh-DHAR chelates could be absorbed onto the front of the enrichment column when they were injected into the injector and sent to the enrichment column [ZORBAX Stable Bound, 4.6 x 10 mm, 1.8 microm] with a 0.05 mol L(-1) of phosphoric acid solution as mobile phase. After enrichment, and by switching the six ports switching valve, the retained chelates were back-flushed by mobile phase and traveling towards the analytical column. The separation of these chelates on the analytical column [ZORBAX Stable Bound, 4.6 x 50 mm, 1.8 microm] was satisfactory with 54% acetonitrile (containing 0.05 mol L(-1) of phosphoric acid and 0.1% of tritonX-100) as mobile phase. Palladium, platinum and rhodium were separated completely within 2 min. By on-line enrichment technique, the enrichment factor of 100 was achieved, and the detection limits (S/N = 3) of palladium, platinum and rhodium reaches 1.4 ng L(-1), 1.6 ng L(-1) and 2.0 ng L(-1), respectively. This method was applied to the determination of palladium, platinum and rhodium in water, urine and soil samples with good results.

Simultaneous determination of palladium, platinum, rhodium and gold by on-line solid phase extraction and high performance liquid chromatography with 5-(2-hydroxy-5-nitrophenylazo)thiorhodanine as pre-column derivatization regents.

In this paper, 5-(2-hydroxy-5-nitrophenylazo)thiorhodanine (HNATR) was synthesized. A new method for the simultaneous determination of palladium, platinum, rhodium and gold ions as metal-HNATR chelates was developed using a rapid analysis column high performance liquid chromatography equipped with on-line solid phase extraction technique. The samples (Water, human urine, geological samples and soil) were digested by microwave acid-digestion. The palladium, platinum, rhodium and gold ions in the digested samples were pre-column derivatized with HNATR to form colored chelates. The Pd-HNATR, Pt-HNATR, Rh-HNATR and Au-HNATR chelates can be absorbed onto the front of the enrichment column when they were injected into the injector and sent to the enrichment column [Zorbax Stable Bound, 10 mm x 4.6 mm, 1.8 microm] with a buffer solution of 0.05 mol L(-1) phosphoric acid as mobile phase. After the enrichment had finished, by switching the six ports switching valve, the retained chelates were back-flushed by mobile phase and travelling towards the analytical column. These chelates separation on the analytical column [Zorbax Stable Bound, 10 mm x 4.6 mm, 1.8 microm] was satisfactory with 72% acetonitrile (containing 0.05 mol L(-1) of phosphoric acid and 0.1% of Triton X-100) as mobile phase. The palladium, platinum, rhodium and gold chelates were separated completely within 2.5 min. Compared to the routine chromatographic method, more then 80% of separation time was shortened. By on-line solid phase extraction system, a large volume of sample (10 mL) can be injected, and the sensitivity of the method was greatly improved. The detection limits (S/N=3, the sample injection volume is 10 mL) of palladium, platinum, rhodium and gold in the original samples reaches 1.4, 1.8, 2.0 and 1.2 ng L(-1), respectively. The relative standard deviations for five replicate samples were 2.4-3.6%. The standard recoveries were 88-95%. This method was applied to the determination of palladium, platinum, rhodium and gold in human urine, water and geological samples with good results.

Biomonitoring of titanium, mercury, platinum, rhodium and palladium in dental health care workers.

BACKGROUND: In dentistry, titanium, mercury, platinum, rhodium and palladium are used to produce dental fillings. Therefore, dental workers who apply such materials may be exposed to these metals. METHODS: The study concerned 40 healthy subjects-20 controls and 20 dental health care workers-to determine serum and urinary levels of the aforementioned metals by inductively coupled plasma mass spectrometry. RESULTS: Mean urinary and serum titanium did not reveal statistically significant differences in the two groups. The very low urinary and serum levels of mercury, platinum, rhodium and palladium prevented us from making a statistical evaluation between the two groups. CONCLUSIONS: We did not find a significant increase in serum and urinary titanium levels in dental health care workers. Measurement of mercury, platinum, rhodium and palladium in urine and serum was not useful in determining occupational exposure.