PIXE analysis of peanuts planted in Japan and imported from abroad

Elemental concentrations in Chinese peanuts have been analyzed and compared with those in Japanese peanuts by means of a PIXE (Particle Induced X-ray Emission) technique with an internal standard method to investigate traces of residual agricultural chemicals or toxic elements in them because frequent detection of excessive agrochemical residues in food imported from China has posed serious health concerns to Japanese people. We prepared the samples by separating the peanut seed into two cotyledons (seed leaves) and an embryo. Significant differences in elemental concentrations between Chinese and Japanese peanuts have not been observed as far as the peanut seeds used in the present measurement are concerned. The concentrations of the several elements in the embryo are higher than those in the cotyledon. (author)