Iron, copper and zinc isotope compositions of biological reference materials determined by MC-ICP-MS

Abstract

The transition metals Fe, Cu and Zn are the key elements for life, and their isotope compositions are expected to be a new index to estimate the trophic level of organisms and diagnose human diseases. Therefore, it is important to analyse these isotopes precisely and accurately in biological samples with low Fe, Cu and Zn abundances. In this study, we modify the one-column method to purify Cu–Fe–Zn for isotope analysis. The parameters that could affect the accuracy and precision of isotopic measurement were evaluated. The Fe, Cu and Zn isotope values of nine biological reference materials are reported, including plants, marine and terrestrial animals, human hair and serum. The isotope compositions of plant and marine animal organs are different from terrestrial animals and human organs. The variation ranges of δ⁵⁶Fe, δ⁶⁵Cu and δ⁶⁶Zn from plant and marine animals are −1.23‰ to 0.11‰, 0.39‰ to 0.53‰ and 0.28‰ to 0.87‰, respectively, while those from terrestrial animals and human tissues are −2.40‰ to 0.06‰, −0.33‰ to 2.76‰ and −0.65‰ to 0.24‰, respectively. This one-column method is important to provide comprehensive isotope information for biological individuals and efficient study Fe, Cu and Zn isotope distribution in paleontology and biomedicine fields.