Extraction and spectrophotometric determination of thallium(III) with thiothenoyltrifluoroacetone

A procedure is described for the extractive photometric determination of thallium(III) with thiothenoyltrifluoroacetone in carbon tetrachloride. Thallium(III) is extracted quantitatively at pH 4-5 and the bright yellow extract obeys Beer's law over the Tl(III) concentration range 2.5-17.5 mug/ml, at 440 nm. Thallium(III) can be determined in the presence of a large number of cations and anions.