Although still at an early experimental stage, stable metal isotopes are receiving more attention for their potential use in biomedical research. It is found that understanding the natural variations in metal isotopes may help identify some critical aspects of the homeostatic regulation of these metals. The development of the MC-ICP-MS has made it possible to provide quick and robust assessment of the relatively small isotopic variability of metals (e.g. Fe, Cu and Zn) that have biological significance.

The study investigates the Fe and Cu isotope compositions of total blood, serum and red blood cells from 50 young anonymous blood donors, attempting to connect the isotopic variability to the gender and blood group information.

The plot shows Fe and Cu isotope fractionation in erythrocytes and serum of both men and women, along with the liver data from Jaouen et al. The gender effect reflects faster processing and smaller iron stores in women. The overlap of isotopic compositions between liver and serum reflects the production of ceruloplasmin in the liver.

Cu isotopes were measured on a Nu Plasma HR instrument using wet plasma with Zn added for external normalization, while Fe isotopes were measured on a Nu Plasma 1700 coupled with a DSN-100 desolvation unit. The good inter-element mass bias stability on the Nu Plasma HR instrument and unique capability of the Nu Plasma 1700 in retaining good transmission at high resolutions have made them the instruments of choice for this type of work.

Data source: Albarede et al, Metallomics, 2011, 3, 926–933