Determination of trace elements in wheat flour by x-ray fluorescence analysis and its application to identification of their production area

Abstract

Trace elements in wheat flour were determined by an X-ray fluorescence (XRF) analysis in order to identify their production area. By optimizing the measurement conditions of an energy-dispersive XRF spectrometer equipped with 3-dimentional polarization optics, the analysis of heavy elements at sub-ppm levels was possible, and linear calibration curves for 17 elements (Na, Mg, Al, P, S, Cl, K, Ca, Mn, Fe, Cu, Zn, Br, Rb, Sr, Mo, Cd) in wheat flour were obtained. We determined the trace elements for 63 wheat flour samples that were produced in Japan or imported from overseas. The analytical results were subjected to multivariate analysis to discriminate the domestic and imported wheat flours. Principal-components analysis successfully distinguished the two origins. The present study has demonstrated that the XRF technique can provide a rapid and easy way for the provenance analysis of wheat flours, which will be further applied to the quality control of commercial food products. © 2009 The Japan Society for Analytical Chemistry.