This method has been written to provide two separate digestion procedures, one for
the preparation of sediments, sludges, and soil samples for analysis by flame atomic absorption
spectrometry (FLAA) or inductively coupled plasma atomic emission spectrometry (ICP-AES) and
one for the preparation of sediments, sludges, and soil samples for analysis of samples by Graphite
Furnace AA (GFAA) or inductively coupled plasma mass spectrometry (ICP-MS). The extracts from
these two procedures are not interchangeable and should only be used with the analytical
determinations outlined in this section. Samples prepared by this method may be analyzed by ICPAES
or GFAA for all the listed metals as long as the detecion limits are adequate for the required
end-use of the data. Alternative determinative techniques may be used if they are scientifically valid
and the QC criteria of the method, including those dealing with interferences, can be achieved.
Other elements and matrices may be analyzed by this method if performance is demonstrated for
the analytes of interest, in the matrices of interest, at the concentration levels of interest (See
Section 8.0). The recommended determinative techniques for each element are listed below: