Use of CRM's as mutual calibrating materials and control of syntheti multielement standards as used in INAA

The comparability of analytical results from different laboratories requires accurately known concentrations in the applied standards. Dilution effects of different multielement synthetic standard solutions have been studied by measuring 10–12 different concentrations of the same solution. Peak area comparison of four Certified Reference Materials (CRM's) using one value for the evaluation of the other three repetitively led to the intercomparison (degree of compatibility) of the certified values. The idea of the preparation of each laboratory's secondary reference standard by comparison of synthetic multielement standards with as many CRM's as practically feasible is advocated to improve the reliability of analytical results.