title: A review of recent developments in the speciation and location of arsenic and selenium in rice grain.
abstract: 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.
authors.affiliation: Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK.
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Carey
authors.forename: Enzo
authors.initials: E
authors.lastname: Lombi
authors.forename: Erica
authors.initials: E
authors.lastname: Donner
authors.forename: Martin D
authors.initials: MD
authors.lastname: de Jonge
authors.forename: Tracy
authors.initials: T
authors.lastname: Punshon
authors.forename: Brian P
authors.initials: BP
authors.lastname: Jackson
authors.forename: Mary Lou
authors.initials: ML
authors.lastname: Guerinot
authors.forename: Adam H
authors.initials: AH
authors.lastname: Price
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Meharg
mesh_terms: D001151:Arsenic / Q000032:analysis* / Q000378:metabolism; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control; D005857:Germanium / Q000032:analysis / Q000378:metabolism; D013058:Mass Spectrometry; D012275:Oryza / Q000737:chemistry* / Q000378:metabolism; D012639:Seeds / Q000737:chemistry* / Q000378:metabolism; D012643:Selenium / Q000032:analysis* / Q000378:metabolism; D017356:Synchrotrons
chemical_list: D005857:Germanium; D012643:Selenium; D001151:Arsenic