Evaluation of Essential and Toxic Element Concentrations in Buckwheat by Experimental and Chemometric Approaches

The essential and toxic element concentrations in buckwheat were analyzed by inductively coupled plasma optical emission spectrometer (ICP-OES). The concentration data were subjected to common chemometrics analyses, including correlation analysis (CA), principal component analysis (PCA) and hierarchical cluster analysis (HCA), to gain better understanding of the differences among the tested samples. Our results indicated that the essential and toxic element concentrations were not different between Fagopyrum tataricum (L.) Gaertn and F. esculentum Moench. The element concentrations varied among buckwheat samples from different sources. Commercial tartary buckwheat tea contained several essential elements, thus, could be used as the source of essential elements. The detection of toxic heavy metals in commercial tartary buckwheat tea suggested that safety issue of such buckwheat products should be seriously concerned. Our results also revealed that the place of origin and the processing protocol of tartary buckwheat affected the element concentrations of the commercial form. The implications to the quality control and safety evaluation of buckwheat were extensively discussed.