RELIABILITY OF TRACE-METAL ANALYSES - RESULTS OF INTERCOMPARISON ANALYSES OF A RIVER SEDIMENT AND AN ESTUARINE SEDIMENT

The paper reports on two intercomparison analyses of 18 trace metals in a river sediment and an estuarine sediment. The results obtained by more than twenty working groups reveal clear methodological differences between the two most-used methods, namely, atomic absorption spectrometry (AAS) and instrumental neutron activation analysis (INAA): while the accuracy of the AAS measurements decreased on the average in the 2nd intercomparison analysis (estuarine sediment) in relation to the 1st intercomparison analysis (river sediment), the accuracy of the INAA values improved clearly. Accuracies of the trace metal determination in both sediments - expressed as the double standard deviation of laboratory means - were found between about ±20% and ±90% for the AAS method, and between ±10% and ±50% for the INAA measurements. © 1979 Springer-Verlag.