Concentrations of alkali elements in green tea leaves evaluated using PIXE analysis

The concentrations of alkali elements in Japanese green tea leaves were evaluated using particle-induced X-ray emission (PIXE) analysis combined with an internal standard method to investigate the elution of radioactive cesium into green tea using potassium and rubidium. The concentrations of potassium and rubidium of used tea leaf samples were lower than those of unused samples, whereas no significant differences in the concentrations of the other elements were observed between them. In addition, we found a similarity in the relative concentrations between potassium and rubidium although the other elements showed different aspects. These results suggest that it is possible to investigate the elution of radioactive cesium into green tea using potassium and rubidium as substitutes of cesium.