Separation of Tl(I) and Tl(III) from Environmental Water Samples by Flotation Method Coupled with Zeeman ETAAS Determination

An accurate, fast, and simple method for determination of thallium in environmental water samples with Zeeman electrothermal atomic absorption spectrometry (ZETAAS) by previous flotation preconcentration is given. The possibility of using cobalt(III) hexamethylenedithiocarbamate as a colloidal precipitate collector for simultaneous flotation separation of Tl(I) and Tl(III) from water matrices was studied. All experimental parameters influencing a proper flotation of both thallium ions were ascertained. The developed procedure with Co(HMDTC)₃ is applied for preconcentration and separation of total thallium in water matrix before ZETAAS. The results of ZETAAS analysis are compared with those obtained by inductively coupled plasma-atomic emission spectrometry. The ZETAAS limit of detection of thallium preconcentrated by Co(HMDTC)₃ is 0.031 μ g/L.

Key Words :

• Thallium
• Separation
• Preconcentration
• Colloid flotation
• Cobalt(III) hexamethylenedithiocarbamate
• Collector
• Water
• Determination
• AAS

ACKNOWLEDGMENTS

This work was supported by the Ministry of Education and Science of the Republic of Macedonia, as well as the Scientific and Technical Research Council of Turkey (TÜBITAK).

Notes

D*—dithiocarbamate (HMA-HMDTC).

*Samples for AES-ICP were concentrated 40-fold by evaporation.

^**dH^°—German degree of water hardness.