Elemental analysis of the majority of organic and
inorganic matrices requires the partial or total dissolution
of the sample prior to instrumental analysis. Only a few
direct methods allow the introduction of the sample without
any preparation, as presented in Table 1.1 In these cases
the lack of reliable calibration is the major problem. On
the other hand, sample preparation allows the separation
and/or pre-concentration of analytes and makes possible
the use of several determination methods (Table 1).
Sample preparations involve digestion, extraction and
preparation of the analytes before the analysis,2-8 so this
step is time limiting, requiring ca. 61% of the total time to
perform the complete analysis, and is responsible for 30%
of the total analysis error.7 Nowadays the goals to be reached
are the best results, in the shortest time, with minimal
contamination, low reagent consumption and generation
of minimal residue or waste.
In order to achieve the real objectives of the analysis,
some aspects of sample preparation should be taken into
account, focusing on the chosen procedure. Thus,