optimization of a digestion method using diluted acid in bee pollen samples for determination of fe, mn, and zn by flame atomic absorption spectrometry

In this study, the determination of fe, mn, and zn by flame atomic absorption spectrometry (faas) was performed in nine bee pollen samples from different cities. the efficiency of acid digestion in bee pollen samples using nitric acid at different concentrations (3.5, 7.0, and 14.0 mol l−1) and hydrogen peroxide in a microwave oven was evaluated. the proposed procedure using nitric acid diluted to 3.5 mol l−1 was effective for the digestion of all the pollen samples. the samples showed low levels of fe. however, mn and zn were the elements which presented the highest concentrations in the samples. the bee pollen samples studied showed a great mn and zn contribution to the recommended daily intake (rdi) of the human diet, contributing with 71.7 and 15.1 %, respectively. the accuracy of the measurements by faas was evaluated by adding aliquots of the elements in the digestates. recoveries obtained ranged from 89 to 106 % for fe, 94 to 100 % for mn, and 88 to 108 % for zn.