Fully automated dual-column purification procedure for Pb from biological materials for subsequent high-precision isotopic analysis

Abstract

A fully automated dual-column purification procedure for Pb from biological samples, designed for subsequent Pb isotopic analysis, is presented that utilizes the prepFAST MC™ system (Elemental Scientific), Nobias Chelate-PA1 resin (Hitachi High-Tech Fielding Corporation) and DGA resin (TrisKem International). The procedure developed allows the unattended processing of approx. 15–20 samples per day and offers several advantages: low and reproducible blanks (<0.05 ng), no carry over or memory effects, high reusability (>50 uses), high Pb yields (99% ± 15%, 2 SD, N = 23), and strong robustness to matrix variations across biological samples (i.e., bone, hair). Additionally, Pb isotopic analysis using MC-ICP-MS showed no significant on-column fractionation. The measured ²⁰⁸Pb/²⁰⁶Pb, ²⁰⁷Pb/²⁰⁶Pb, and ²⁰⁸Pb/²⁰⁴Pb isotope abundance ratios of biological reference materials (i.e., NIST SRM 1400, ERM-DB001, GBW07601) are consistent with published values. For the hair reference material GBW09101, a ²⁰⁸Pb/²⁰⁶Pb isotope abundance ratio of 2.12045 ± 0.00054 (i.e., δ(²⁰⁸Pb/²⁰⁶Pb)_SRM981 = −21.99‰ ± 0.24‰) (U, k = 2), a ²⁰⁷Pb/²⁰⁶Pb isotope abundance ratio of 0.86292 ± 0.00014 (i.e., δ(²⁰⁷Pb/²⁰⁶Pb)_SRM981 = −56.56‰ ± 0.14‰) (U, k = 2), and a ²⁰⁸Pb/²⁰⁴Pb isotope abundance ratio of 38.451 ± 0.022 (i.e., δ(²⁰⁸Pb/²⁰⁴Pb)_SRM981 = 47.09‰ ± 0.51‰) (U, k = 2) are proposed.