Radiochimica Acta 73, 145-147 (1996)

Speciation of Aquatic Heavy Metals in Humic Acids by ^111mCd/^199mHg TDPAC

 By H. Kupsch, K. Franke, D. Degering*, W. Tröger and T. Butz

 Fakultät für Physik and Geowissenschaften, Universität Leipzig, Germany
* Institut für Nukleare Entsorgungstechnik, Forschungszentrum Karlsruhe, Germany

(Received November 15. 1995; revised version accepted February 16, 1996)

CD(II) / HG(II) / Humic acid complexes / Speciation / Nuclear Quadrupole Interaction (NQI) / Time Differential Perturbed Angular Correlation (TDPAC)

Summary

In order to study the interaction of humic acids with Cd²⁺ and Hg²⁺ the nuclear quadrupole interaction (NQI) of ^111mCd and ^199mHg in humic acids was determined by time differential perturbed angular correlation of gamma-rays (TDPAC). The ^199mHg-NQI's are strongly influenced by the Hg²⁺/humic acid stoichiometry. At low Hg²⁺ loads Hg²⁺ is preferentially two-fold coordinated, higher Hg²⁺ loads lead to higher coordination numbers. For ^111mCd only unspecific binding was observed without any significant changes upon different Cd²⁺ loads.