The drying process of fresh plant materials may affect the porous structure, dehydration and a number of quality characteristics
of these materials. Therefore, this study has investigated the effect of different drying processes on the variation of metal
and metalloid concentrations in the dried plant materials. Seven varieties of native plant species collected from São Domingos
mine were analyzed by instrumental neutron activation analysis (INAA) to investigate the effects of freeze-drying (FD), ambient
air-drying (AAD) and oven-drying (OD) process on the concentrations of metals and metalloids in the plant biomass. Comparison
of ambient air-dried, oven-dried and freeze-dried preparations allows a phenomenological description of the dehydration artefacts.
In the quantitative analysis of metals and metalloids, FD and OD plant samples show the higher concentrations of metals and
metalloids when compared to those in the AAD plant biomass. The freeze-drying process is comparatively reliable for determination
of metals and metalloids concentrations in plant materials.