[Problems related to trace element determination in biological materials].

Analytical problems related to the determination of ultratrace elements such as Cr, Cd, Co, Ni, V in biological materials are described. Prevention of contamination from analytical devices, reagents and the environment is a crucial factor to achieve ultratrace analysis; a stainless steel needle cannot be used for the Cr determination in human serum. Careful examination of the impurity in the labowares and reagents is definitely required prior to analysis. In graphite furnace atomic absorption spectrometry, appropriate background correction is most important to obtain accurate analytical data for biological materials. Appropriate selection of matrix modifier(s) can reduce background signals to a negligible level. In ICP mass spectrometry mass overlapping by polyatomic ions is a most serious problem for the determination of most essential trace elements. Biological certified reference materials (CRMs) are of great value to assess accuracy of analytical results. However, the availability of human serum reference materials representative of normal values has been limited. Development of such biological reference materials (human serum, urine) is urgently required for analytical quality assurance.