A new method for extracting and purifying lead from difficult matrices for isotopic analysis

A new low blank separation scheme for lead is presented for the preparation of ultrapure lead samples for isotopic analysis by thermal ionisation mass spectrometry. The method benefits from the selectivity and high capacity of a new extraction chromatographic material: Sr.Spec(TM). The use of this material in HCl media, rather than the more usual HNO3 media, affords a straightforward separation of Pb from complex metal ores with high yield, good purity and satisfactory blank levels on very small (0.1 ml) columns using small volumes of solutions of a single mineral acid. It has the advantages that it also separates Pb from Bi in the same column that separates Pb from matrix elements and that, unlike other low blank methods for Pb, it is directly applicable to the separation of traces of Pb from tin metal samples.