Speciation and distribution of arsenic and localization of nutrients in rice grains

Journal Article · Wed Sep 05 00:00:00 EDT 2012 · New Phytol.

DOI:https://doi.org/10.1111/j.1469-8137.2009.02912.x· OSTI ID:1047325

Lombi, E; Scheckel, K G; Pallon, J; Carey, A M; Zhu, Y G; Meharg, A A ^[1]

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1. EPA

Arsenic (As) contamination of rice grains and the generally low concentration of micronutrients in rice have been recognized as a major concern for human health. Here, we investigated the speciation and localization of As and the distribution of (micro)nutrients in rice grains because these are key factors controlling bioavailability of nutrients and contaminants. Bulk total and speciation analyses using high-pressure liquid chromatography (HPLC)-inductively coupled plasma mass spectrometry (ICP-MS) and X-ray absorption near-edge spectroscopy (XANES) was complemented by spatially resolved microspectroscopic techniques ({mu}-XANES, {mu}-X-ray fluorescence ({mu}-XRF) and particle induced X-ray emission (PIXE)) to investigate both speciation and distribution of As and localization of nutrients in situ. The distribution of As and micronutrients varied between the various parts of the grains (husk, bran and endosperm) and was characterized by element-specific distribution patterns. The speciation of As in bran and endosperm was dominated by As(III)-thiol complexes. The results indicate that the translocation from the maternal to filial tissues may be a bottleneck for As accumulation in the grain. Strong similarities between the distribution of iron (Fe), manganese (Mn) and phosphorus (P) and between zinc (Zn) and sulphur (S) may be indicative of complexation mechanisms in rice grains.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
• Sponsoring Organization: USEPA
• OSTI ID: 1047325
• Journal Information: New Phytol., Vol. 184, Issue (1) ; 10, 2009; ISSN 0028-646X
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
60 APPLIED LIFE SCIENCES
ABSORPTION
ARSENIC
BUILDUP
COMPLEXES
CONTAMINATION
DISTRIBUTION
EMISSION
ENDOSPERM
FLUORESCENCE
HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY
HUMAN POPULATIONS
IRON
MANGANESE
MASS SPECTROSCOPY
NUTRIENTS
PARTICLES
PHOSPHORUS
PLASMA
RICE
SPECTROSCOPY
TRANSLOCATION
ZINC