Radioisotope induced X-ray fluorescence analysis is a rather simple and convenient method for investigating ashed plant material.
In order to reduce matrix effects, thin samples (2 mg/cm2) are analyzed to obtain a reasonable compromise between maximum sensitivity and the lowest possible absorption effects. Concentrations
are determined by standard addition method. A precision of 6–8% can be achieved. As an application, analytical results are
given for whole grains of several sorts of wheat.