Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)This work aims to assess a method for total Hg quantification in soil and leaf samples by using a Direct Mercury Analyzer(R) (DMA-80 TRICELL; Milestone Inc., Italy). Standard Reference materials of tree leaves, river sediment and soil, and collected samples of soil and leaves were used to optimize and to validate the method. Given that the technique allows direct analysis of samples by combustion, aspects like effect of sample amount variation and sample granulometry were considered. Method's robustness was also assessed through the Youden test showing that for leaf sample analyses, among the seven tested factors, four were able to significantly affect the analytical results, but the soil samples results were not significantly affected by slight variations of any of the seven factors. Recoveries for reference materials ranged from 102% to 104%, and the precision (RSD) was lower than 5%.241118801886Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2010/19040-4]