The importance of assessing variability in the distribution of anthropogenic palladium, platinum and rhodium in fluvial sediments

Abstract

The distribution and behaviour of anthropogenic platinum-group elements (PGE) in river systems has as yet attracted little attention. Aquiring good quality data in PGE analysis poses a serious challenge to the environmental chemist, not in the least due to the low concentrations at which the PGE are currently found in the environment. Using the River Stour in Kent, U.K. as a case study, the work presented in this paper focuses specifically on the spatial and temporal variability of PGE in fluvial sediments. The analysis of river bed sediments shows high variability both on a catchment scale and on a local scale within sample sites. Moreover, high relative standard deviation points to a heterogeneous distribution of PGE within sediment samples, which is characteristic of the elements and is commonly known as the nugget effect. If unassessed, analytical data are unlikely to be truly representative and the interpretation of PGE data could be inherently flawed. For this reason this paper suggests a need to include thorough quantification and reporting of this variability as a matter of practice in the acquisition of environmental PGE data. © 2006 Springer-Verlag Berlin Heidelberg.