Tl-speciation of aqueous samples - a review of methods and application of IC-ICP-MS/LC-MS procedures for the detection of (CH3)2Tl+ and Tl+ in river water

This study provides an overview on Tl-speciation methods developed in the last years. Most of them require transformation of a species and do not allow direct detection of the species of interest. LC-MS and IC-ICP-MS methods are optimised for direct analysis of the Tl-species Tl+ and (CH3)(2)Tl+ (dimethylthallium (DMT)) in freshwater on a ng L-1 level. The methods are applied in a study of water from Vicht River in Stolberg (Germany). Tl+ is shown to be at least in part derived from anthropogenic sources among which the industrial sources may be significant. The natural occurrence of DMT is proven, although this Tl-species is temporally variable in abundance and Tl+ predominates.