Determination of Cu, Fe, Mn e Zn using FAAS in cassava (Manihot esculenta crantz) roots from eastern amazon

Abstract

The aim of this work is to determine the amount of Fe, Zn, Mn and Cu in nine samples of cassava roots by Flame Atomic Absorption Spectrometry using chemometrics tools such as multivariate exploratory analysis to explain possible differences in its chemical characteristics and Tukey test to verify the statistical significance of the mean values. Four samples were obtained from a local trade, cultivated without any information about planting conditions or harvesting. The other five samples belonged to an active germplasm bank (AGB) under known planting conditions. The Fe content ranged from 0.54 to 5.24 mg/kg, Zn from 0.38 to 6.55 mg/kg, Cu from 0.04 to 0.89 mg/kg and Mn from 0.16 to 0.41 mg/kg. The commercial samples showed expected results for all elements quantified, while AGB samples had advantages in iron and zinc uptake. Samples from local trade did not present iron in their composition, but were the only that showed presence of manganese. Such feature was therefore an essential parameter to distinguish commercials than other samples. The knowledge of planting and environmental conditions is essential to ensure probable exogenous factors that may cause variations in micronutrient uptake. This factors should be taken into account when estimating micronutrient uptake in cassava samples.