Multielemental analysis of human fetal tissues using inductively coupled plasma-mass spectrometry

Inductively coupled plasma-mass spectrometry (ICP-MS) was used to study the distribution of 26 major and trace elements in six tissues from 21 human fetuses aged 16-22 wk. Brain, lung, spleen, kidney, heart, and liver were analyzed following a microwave oven digestion step carried out according to clean techniques designed for ultratrace metal analyses. Precision and accuracy controls were conducted using standard reference material #1577b Bovine Liver. Significant differences among tissues were found for most of the elements. Essential trace elements seem to be increasingly retained as fetal tissues mature and become physiologically functional. The ranges of concentrations measured in fetal tissues at this stage of development are generally lower and much narrower than in adult tissues. The age of the fetus, which is not given in most studies, as well as the different techniques and levels of quality assurance could be responsible for the discrepancies in the trace metal concentrations reported here and in the literature. Intratissue homogeneity was also assessed in five human fetal brains. Frontal, occipital, parietal and temporal lobes, striatum, hippocampus, and thalamus were isolated and analyzed separately. No significant differences were found in the distribution of any of the elements at this stage of development. Because of the relatively narrow ranges of concentrations found for most elements, we believe that the results presented in this study represent the inorganic fingerprint of the main tissues of normal fetuses at midpregnancy for the Greater Montreal area.