Reliable and precise Zn isotopic analysis of biological matrices using a fully automated dual-column purification procedure.

A fully automated dual-column purification procedure for Zn from biological samples, designed for subsequent Zn isotopic analysis, is presented that utilizes the prepFAST MC™ system (Elemental Scientific), DGA resin (TrisKem International), and TK201 resin (TrisKem International). The procedure developed enables the unattended processing of 20 samples per day and is characterized by low and reproduceable blanks (< 1.5 ng), no carry-over or memory effect, high reusability (> 50 times), high Zn yields 100.1% ± 5.3% (2 SD, N = 22), and strong robustness to matrix variations across biological samples (bone, liver, hair, blood). Additionally, Zn isotopic analysis using MC-ICP-MS showed no significant on-column fractionation. The measured δZn/Zn values for NIST SRM 1400 (0.67‰ ± 0.07‰, U, k = 2), NIST SRM 1486 (0.91‰ ± 0.06‰, U, k = 2), NIST SRM 1577c (- 0.45‰ ± 0.05‰, U, k = 2), ERM-DB001 (- 0.35‰ ± 0.05‰, U, k = 2), GBW09101 (- 0.32‰ ± 0.08‰, U, k = 2), and SeroNorm whole blood L-3 (-0.15 ‰ ± 0.05 ‰, U, k = 2) are consistent with published values. The procedure developed makes Zn, an analytically challenging isotope system, more accessible, feasible, and reliable for a broader range of users while enabling high sample throughput.