Single-stage method for the simultaneous isolation of lead and strontium from silicate samples for isotopic measurements

A new scheme for the simultaneous separation of lead and strontium is descr ibed and applied to the determination of isotope ratios in silicate samples . This method is based on the selectivity and high capacity of the extracti on chromatographic material referred to as Sr.Spec. This new procedure affo rds a straightforward separation of Sr and Pb on 150 mul columns, with high Pb yield (>96%), good purity and satisfactory blank levels, using small vo lumes of mineral acids (HNO3 and HCl) easy to purify by sub-boiling distill ation. The degree of purity of the Sr and Pb separates was evaluated by ICP -MS measurements whereas the yields and blanks were determined by ID-TIMS. The validity of the method for isotopic analyses is illustrated by Sr and P b isotopic compositions obtained on basaltic and trachy-andesitic rocks. (C ) 2001 Elsevier Science B.V. All rights reserved.