Analysis of antimony species - lessons learnt from more than two decades of environmental research

The major findings of similar to 20 years of research on the analysis of antimony species in environmental samples are summarised in this paper. The complex chemistry of antimonite (Sb-III) as well as of antimonate (Sb-V) plays a major role in chromatographic speciation of these species. For simple matrices, like surface or ground-water samples, antimony redox speciation has become a routine analysis and is robust and highly reproducible, if certain aspects are taken into consideration. These aspects are the formation of a stable complex of Sb-III and complex formation kinetics. Then the antimony redox species can be separated on an anion-exchange column and detected with a suitable element detector (inductively coupled plasma-mass spectrometry (ICP-MS) or hydride generation-atomic fluorescence spectrometry (HG-AFS)) for trace analysis. The influence of complexing agents in the sample matrix, or in the eluent, on the formation of Sb-III and Sb-V complexes and possible corruption of chromatography is discussed. This ability of antimony to form rather stable complexes also increases the risk of artefact formation during extraction of solid samples.