Comparative study for extraction of Hg(II) with Cyanex-923 from chloride and bromide media and its separation from Cd(II) and Zn(II)

Abstract

Extraction of mercury (II) was carried out from chloride and bromide media with Cyanex-923 in toluene, to find out the effect of media on extraction. The quantitative extraction was observed in the range of 0.01–0.10 mol dm⁻³ HCl with 0.10 mol dm⁻³ Cyanex-923 and in the range of 0.30–0.70 mol dm⁻³ HBr with 0.08 mol dm⁻³ Cyanex-923. The recovery of Hg(II) extracted into organic phases from HCl and HBr media were observed with the mixture of 5.0 mol dm⁻³ HNO₃+4.0 mol dm⁻³ HCl and 2.0 mol dm⁻³ HNO₃, respectively. The stoichiometric ratio of Hg(II): Cyanex-923 was 1:2 for both the media.

On the basis of extraction and stripping study, the separation of Hg(II) from Cd(II) and Zn(II) was carried out. These methods were successfully applied for the analysis of Hg(II) in real samples.

Keywords:

• Extraction
• Mercury(II)
• Cyanex-923
• Hydrochloric acid
• Hydrobromic acid
• Stripping
• Separation

Acknowledgments

The authors are thankful to Cytec Industries Inc., Canada, for supplying Cyanex-923 as gift sample.