Speciation analysis of thallium in water samples after separation/preconcentration with the Empore™ chelating disk

Abstract

A simple, reliable and novel solid phase extraction procedure using the Empore™ chelating disk has been developed for determination of Tl(I) and Tl(III) in environmental water samples by electrothermal atomic absorption spectrometry (ETAAS). The influence of humic acids on separation/preconcentration of thallium species with the Empore™ chelating disk is investigated. The preconcentration factor and detection limit are 500 and 5 ng L⁻¹, respectively. The recoveries are in the range 93–103% for mineral, pond, sea, snowmelt, waste waters at 28–500 ng L⁻¹ Tl and in the range 82–112% for river waters at 18–28 ng L⁻¹ Tl.

Keywords:

• thallium speciation
• Empore chelating disk
• ETAAS
• humic acids
• interferences, water analysis

Acknowledgement

The authors gratefully acknowledge the financial support provided by the Bulgarian Ministry of Education (N ВУ-Х-207/06).