The use of total-reflection X-ray fluorescence to track the metabolism and excretion of selenium in humans

Selenium and other trace elements (Cu, Zn, Br, and Rb) were determined in human blood serum and urine samples with the aim of studying both the intestinal absorption and the rate of selenoprotein synthesis in the liver after a single oral dose ingestion of sodium selenite. The results obtained confirm those already observed in experiments with rats where, as in humans, a peak of Se becomes evident within 3-4 h in the plasma and then the values slightly decrease. While on the contrary, urinary Se excretion progressively increases. The quantitative measurement of trace elements in human fluids can be performed so quickly and simply that it can assume the significance of a routine functional test. (C) 1999 Published by Elsevier Science B.V. All rights reserved.