Some uncertainties associated with preparation of standards in organic matrix

Until recently no techniques which have multielement detection capability, high sensitivity and good spatial resolution in relatively thick tissue section have existed. The use of proton induced x-ray emission (PIXE) and synchrotron radiation induced x-ray emission (SRIXE) using proton and x-ray microbeams changed this situation. However there are some difficulties with the existing standards for quantitatively calibrating the trace elements concentration in biological material. For the purpose of our experiments a special technique of standard production was applied. (orig.)