Abstract

RODRIGUEZ-SALAZAR, M. T. et al. Development and validation of an analytical method for the determination of lead isotopic composition using ICP-QMS. Geofís. Intl [online]. 2010, vol.49, n.3, pp.113-117. ISSN 2954-436X.

This work reports a method for the precise and accurate determination of Pb isotope composition in soils and geological matrices by ICP-QMS. Three reference materials (AGV-2, SRM 2709 and JSO-1) were repeatedly measured, using ICP-QMS instruments in order to assess the quality of this analytical procedure. Mass discrimination was evaluated for Pb/Pb with Pb isotope reference material NIST SRM 981, and the correction applied to the above mentioned reference materials to achieve good accuracy of the analytical methodology. An internal standardization using ²⁰⁵Tl was employed to avoid instrumental drift. The measured isotope compositions of all analyzed reference material were comparable with the reported (JSO-1 and SRM 2709) and certified values (AGV-2). The accuracy results agreed in average within 0.002% for ²⁰⁷Pb/²⁰⁴Pb and 0.825% for ²⁰⁷Pb/²⁰⁶Pb. These data corroborate that ICP-QMS results to be reliable in terms of accuracy and precision, for the determination of the Pb isotopic compositions in soils and geological matrices.

Keywords : ICP-QMS; lead isotope composition; analytical methodology; reference material.