Selective preconcentration of thallium on modified silica gel for its determination by flame emission and absorption spectrometry

Thallium (0.02-20 mug) was successfully preconcentrated on silica gel C18 from 0.1M hydrochloric acid in the presence of various cationic surfactants as ion pairs with tetrachlorothallate(III), and subsequently eluted with 96% ethanol. Of various atomic spectrometric procedures considered, emission spectrometry in a nitrous oxide-acetylene flame is suitable for the final determination of thallium in plants, this is more sensitive for thallium than flame atomic absorption spectrometry.