Elemental analysis of samples of biological origin relative to their protein content by means of charged particle bombardment.

The particle-induced X-ray emission (PIXE) method and the 14N(d,p)15N nuclear reaction are combined for simultaneous trace element and nitrogen determination. Measurement of nitrogen content often allows the relating of the elemental concentrations determined by PIXE to the protein content of the sample. For the measurements only a small amount of sample material is needed; therefore, it is possible to keep track of the quantity of a certain element in the successive steps of a biomedical separation process. In about 10 min, trace element concentrations in the ppm range can be determined with a statistical accuracy of about 10%.