Chronological information for meteorite formation enhances our understanding of cosmic events within our solar system. Dating the formation of iron (Fe) based meteorites may be accomplished with halfnium (Hf) and tungsten (W) isotopic ratios. During their formation, Hf and W fractionate between liquid metal and liquid silicate phases. The extinct radionuclide 182Hf (t1/2 9x106 yrs), which was present during the formation of our solar system, can be used as a chronometer for this fractionation, allowing ratios of 180Hf/184W and 182W/184W to estimate the 182Hf/180Hf at the time of meteorite formation. Sample analysis is typically accomplished by mass spectrometry, and isobaric interference must be minimized, in particular, at mass 180. Consequently, elemental separations of tantalum (Ta), W and Hf are required. Previous methods have yielded incomplete separation of Hf/Ta/W. An improved chromatographic method has been developed for the separation of Hf/Ta/W. The method is described, along with performance optimization to maximize resolution and separation efficiency.

Chromatographic separation of Hf/Ta/W

247th National Meeting (2014)

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