A review of recent developments in the speciation and location of arsenic and selenium in rice grain

Anal Bioanal Chem. 2012 Apr;402(10):3275-86. doi: 10.1007/s00216-011-5579-x. Epub 2011 Dec 8.


Rice is a staple food yet is a significant dietary source of inorganic arsenic, a class 1, nonthreshold carcinogen. Establishing the location and speciation of arsenic within the edible rice grain is essential for understanding the risk and for developing effective strategies to reduce grain arsenic concentrations. Conversely, selenium is an essential micronutrient and up to 1 billion people worldwide are selenium-deficient. Several studies have suggested that selenium supplementation can reduce the risk of some cancers, generating substantial interest in biofortifying rice. Knowledge of selenium location and speciation is important, because the anti-cancer effects of selenium depend on its speciation. Germanic acid is an arsenite/silicic acid analogue, and location of germanium may help elucidate the mechanisms of arsenite transport into grain. This review summarises recent discoveries in the location and speciation of arsenic, germanium, and selenium in rice grain using state-of-the-art mass spectrometry and synchrotron techniques, and illustrates both the importance of high-sensitivity and high-resolution techniques and the advantages of combining techniques in an integrated quantitative and spatial approach.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Arsenic / analysis*
  • Arsenic / metabolism
  • Food Contamination / analysis
  • Food Contamination / prevention & control
  • Germanium / analysis
  • Germanium / metabolism
  • Mass Spectrometry
  • Oryza / chemistry*
  • Oryza / metabolism
  • Seeds / chemistry*
  • Seeds / metabolism
  • Selenium / analysis*
  • Selenium / metabolism
  • Synchrotrons


  • Germanium
  • Selenium
  • Arsenic