Evaluation of conventional dry ashing and wet digestionmethodsfor determination of Fe, Mn, Ni, Cu, Co, Mg, Zn, Ca, Mo e Se levelsin dried samples of organic tomatoes (Solanum lycopersicum L.)by Flame Atomic Absorption Spectrometry (FAAS)

The aim of this study was to investigate the effect of digestion and extraction of minerals in organic tomatoes toatomic spectrometry. Fe, Mn, Ni, Cu, Co, Mg, Zn, Ca, Mo e Se levels in seven organic samples of dried tomatoes(Solanum lycopersicum L.), were determined by flame atomic absorption spectrometry. Dissolution conditions in thewet digestion method were studied by investigating several variables, including type of acid mixture and acidvolume and digestion time. Comparison with conventional dry ashing methods was also made. In order to check theelement losses during digestion and the accuracy of the results, all tests were repeated with statistical analysis. Thenitric-perchloric acid digestion method was efficient for Ca, Mg, Se and Zn. The extraction procedure with chlorideacid was similar to the nitric-perchloric acid digestion and the nitric-perchloric acid digestion was equivalent to theconventional dry ashing for the Mn. For the Cu and Mo conventional dry ashing methods was more efficient. Forthe Ca conventional dry ashing methods no showed significative difference for the nitric-perchloric acid digestion.The extractions with chloride acid are promised, practical and simples, with lower riscs for the manusead andambiental contaminations.