3. Results and discussion
3.1. Spiked calibration standard
To determine the concentration of K and Mg in spiked wood, filter
paper and babassu mesocarp, the matrices were analyzed by
ICP OES after acid decomposition. The estimated LOQ were 188.6
and 1.8 lg g1 for K and Mg, respectively. Mass fractions of these
analytes for the spiked materials are presented in Table 1. The
accuracy of the proposed method was checked by the analysis of
SRM 1515 and SRM 1537, which accorded a 95% confidence level
when compared to the certified value (Table 1).