A THEORETICAL ADAPTATION OF THE CLASSICAL ISOTOPE-DILUTION TECHNIQUE FOR PRACTICAL ROUTINE ANALYTICAL DETERMINATIONS BY MEANS OF INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY

The classical isotope dilution approach is adapted for routine element determinations by inductively coupled plasma mass spectrometry (ICP-M S). In the approach described a calibration graph, which is curved by definition, is used as reference. This calibration graph can be derive d both theoretically and practically by measuring known element concen trations. It is shown that deliberately introduced instrumental sensit ivity changes are completely corrected for. The analytical consequence s in terms of curvature of the calibration graph, blank determinations and detection limits are described and discussed.