Abhängigkeit der Chlor-Isotopenseparation vom Vernetzungsgrad eines stark basischen Anionenaustauschers / Dependence of Chlorine Isotope Separation on the Degree of Cross Linkage of a Strongly Basic Anion Exchange Resin

Using ion exchange chromatography, the dependence of the chlorine isotope separation on the degree of cross linkage of a strongly basic anion exchange resin was investigated. With increasing degree of cross linkage the elementary separation effect for the two stable isotopes 35Cl and 37Cl increases. In all experiments 35Cl- is enriched in the resin phase, whereas 37Cl- is enriched in the solution, using 0.1 M NaNO3 as an eluant. Within the degree of cross linkage of 2 to 10 per cent investigated, there is a linear correlation of the elementary separation effect of the chlorine isotopes with the selectivity coefficient between the ions NO3- and Cl-. The results show that the electrolyte behavior of anionic isotope exchange reactions is comparable with that of cations. The 35Cl/37Cl isotope ratio is determined using thermal ionization mass spectrometry.