Evaluation of quantitative synchrotron radiation micro-X-ray fluorescence in rice grain

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Journal of Synchrotron Radiation
Concentrations of nutrients and contaminants in rice grain affect human health, specifically through the localization and chemical form of elements. Methods to spatially quantify the concentration and speciation of elements are needed to protect human health and characterize elemental homeostasis in plants. Here, an evaluation was carried out using quantitative synchrotron radiation microprobe X-ray fluorescence (SR-µXRF) imaging by comparing average rice grain concentrations of As, Cu, K, Mn, P, S and Zn measured with rice grain concentrations from acid digestion and ICP-MS analysis for 50 grain samples. Better agreement was found between the two methods for high-Z elements. Regression fits between the two methods allowed quantitative concentration maps of the measured elements. These maps revealed that most elements were concentrated in the bran, although S and Zn permeated into the endosperm. Arsenic was highest in the ovular vascular trace (OVT), with concentrations approaching 100 mg kg−1 in the OVT of a grain from a rice plant grown in As-contaminated soil. Quantitative SR-µXRF is a useful approach for comparison across multiple studies but requires careful consideration of sample preparation and beamline characteristics.
This article was originally published in Journal of Synchrotron Radiation. The version of record is available at: https://doi.org/10.1107/S1600577523000747
arsenic, metal(loid)s, rice bran, rice grain, synchrotron radiation microprobe X-ray fluorescence, SR-µXRF
Limmer, Matt A., Samuel M. Webb, and Angelia L. Seyfferth. “Evaluation of Quantitative Synchrotron Radiation Micro-X-Ray Fluorescence in Rice Grain.” Journal of Synchrotron Radiation 30, no. 2 (2023): 407–16. https://doi.org/10.1107/S1600577523000747.