Trace elements (zinc, cobalt, selenium, rubidium, bromine, gold) in human placenta and newborn liver at birth.

Concentrations of zinc, cobalt, selenium, rubidium, bromium, and gold have been determined by neutron activation analysis in 18 placental and 6 liver tissue samples at birth. Their respective mean concentrations +/- standard deviations (parts per million) were 58 +/- 10, 0.060 +/- 0.036, 1.90 +/- 0.41, 14.0 +/- 3.5, 26.9 +/- 14.3, and 0.31 +/- 0.14 in placenta, and 651 +/- 257, 0.156 +/- 0.077, 4.52 +/- 1.96, 9.2 +/- 3.7,11.2 +/- 4.1, and 0.12 +/- 0.06 in liver tissue. Thus, we observed that the mean concentrations of essential trace elements (zinc, cobalt, and selenium) were significantly higher in liver than in placenta, whereas the nonessential trace elements (rubidium, bromium, and gold) were found in significantly higher concentrations in placenta than in liver tissue.