Preparation of reference materials for determination of cadmium in rice grain by X-ray fluorescence spectrometry

Tetsuo Inui, Saki Nakatao, Yuya Koike, Masaru Kitano, Toshihiro Nakamura

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A preparation method of Cd-containing rice grain was developed for X-ray fluorescence (XRF) analysis. Cd-containing rice grain was prepared by putting the base rice grain (white rice; Akita, Japan) into methanol containing an appropriate amount of Cd and then heating and cooling. The resulting rice grain was packed into a polyethylene cup (32 mm internal diameter ×23 mm height) covered with a 6-μm-thick polypropylene film for XRF analysis. In the XRF measurement of Cd Kα, Cd-containing rice grain had a sufficient durability, stability, and repeatability. The calibration curve of Cd constructed with a suite of Cd-containing rice grains showed good linearity (r = 0.996) in the range of 0.50 - 9.8 mg kg-1, whose concentrations of Cd were determined with atomic absorption spectrometry (AAS) using HNO3-H2SO4 decomposition after the XRF measurements. The lower limit of detection of Cd was 0.13 mg kg-1. The target concentrations of Cd in rice grains were in good agreement with the values obtained by AAS after acid decomposition.

Original languageEnglish
Pages (from-to)925-930
Number of pages6
Issue number10
Publication statusPublished - 2013


  • Cd
  • Reference material
  • Rice grain
  • X-ray fluorescence analysis

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