Determination of selenium in domestic or imported buckwheat and barley using inductively coupled plasma-mass spectrometry

Abstract

Inductively coupled plasma-mass spectrometry (ICP-MS) was applied to determination of selenium (Se) in food samples. When the concentration of nitric acid in the sample solution was adjusted to 1.0 to 1.5 M, a suitable analytical value of Se was obtained without using any internal substances. The concentration detection limit was 25 ng/g in the dried food samples. In quadruplicate assays of 7 biological reference materials using the proposed ICP-MS method, measured Se concentrations were not significantly different from their certified values. Using the proposed method, Se concentrations in domestic or imported buckwheat and barley were determined. Imported cereals grown in Manitoba (Canada) or North Dakota (USA), known to be high Se areas, showed high Se values at a level of more than 300 ng/g, while most domestic cereals showed low Se values at a level of less than 100 ng/g. These results indicate that the proposed method is reliable and suitable for the determination of trace levels of Se in foods.