Speciation of Pt(II) and Pt(IV) in spiked extracts from road dust using on-line liquid chromatography-inductively coupled plasma mass spectrometry.

The emission of platinum from automobile catalytic exhaust converters is well known and the accumulation of Pt in road dust has been studied by the analysis of total Pt contents. However, there are few studies on the speciation of the emitted Pt-compounds in the environment. A separation method with HPLC-UV has been developed by Nachtigall et al. [Chromatogr. A 775 (1997) 197] with aqueous standards of Pt(II)- and Pt(IV)-chloro complexes. Due to the limited selectivity and sensitivity of the UV-detection this method is not suitable for Pt-speciation in road dust extracts. Therefore, in this study the method of Nachtigall et al. was modified to realize an on-line coupling to ICP-MS with the advantage of Pt-specific detection. Calibration was performed with aqueous standards and spiked road dust extracts. Calibration curves were linear with low residual standard deviation (1.3-3.1% for the aqueous standards) and approximately 10-times lower detection limits compared to the HPLC-UV-method. Moreover, the stability of the model species was investigated using isocratic as well as gradient separation. Isotopic ratios of 194Pt, 195Pt, 196Pt and 198Pt were determined for quality control. A new mathematical correction method for the HfO-interference on the 195Pt-signal was developed. Additionally, the elution pattern of further elements in the road dust extracts was monitored and total element contents were determined in unspiked road dust extracts.

[1]  Jeffrey T. Miller,et al.  An EXAFS study of the co-ordination chemistry of hydrogen hexachloroplatinate(IV). 1. Speciation in aqueous solution , 2002 .

[2]  P. Quevauviller,et al.  A new certified reference material for the quality control of palladium, platinum and rhodium in road dust, BCR-723 , 2002 .

[3]  G. Wünsch,et al.  Speciation of platinum–chloro complexes and their hydrolysis products by ion chromatography: Determination of platinum oxidation states , 1997 .

[4]  V. Hodge,et al.  Platinum and palladium in roadside dust. , 1986, Environmental science & technology.

[5]  E. Helmers,et al.  Geochemical behaviour of platinum-group elements (PGE) in particulate emissions by automobile exhaust catalysts: experimental results and environmental investigations , 1997 .

[6]  B. Michalke,et al.  Platinum determination in nutrient plants by inductively coupled plasma mass spectrometry with special respect to the hafnium oxide interference , 1997 .

[7]  B. Michalke,et al.  Analysis for the stability of platinum‐containing species in soil samples using capillary electrophoresis interfaced on‐line with inductively coupled plasma mass spectrometry , 1997 .

[8]  E. Blasius,et al.  Lehrbuch der analytischen und präparativen anorganischen Chemie , 1952 .

[9]  J. Pepys,et al.  Immediate (type I) allergic responses to platinum compounds , 1976, Clinical allergy.

[10]  M. Lederer,et al.  Studies of platinum(II) compounds in aqueous solution. Part 1. K2PtCl4 , 1997 .

[11]  U. Heinrich,et al.  Bioavailability of platinum emitted from automobile exhaust. , 1998, Toxicology letters.