Determination of selenium in rat brain by synchrotron radiation X-ray fluorescence

Selenium, an ubiquitous essential trace-element, is known to be particularly difficult to measure especially in brain. First, it is a non metal, next, at very low concentration (below ppm); at last, the brain matter, very rich in lipids, make the diges- tion specially uneasy. Using synchrotron radiation induced X-ray fluorescence analysis (SXRF), selenium in rat brain was mea- sured equal to CSe = 124 ± 5.4 ppb with a MDL (minimum detection limit) of 20 ppb. The obtained values should be used as a first step to study human brain on extremely small and specific locations. With the development of aging pathologies (such as Alzheimer's or Parkinson's disease...), it matters to get informations about selenium known as an anti-aging element. The obtai ned values from rat, near of man's, may also highlight it as a potential animal model system for studying selenium in human brain.