3.1.3. Evaluation of the sample mass in the direct analysis
The matrix effects were evaluated by varying the mass of the
material under analysis. Initially some samples of tree nut were
selected randomly and different amounts (50, 100 and 150 mg)
were weighed and analyzed. The absorbance of the direct
measurement of samples and after the pre-concentration of
successive ashing processes and amalgamation for the same
sample were compared.