Determina??o dos teores de cobre em diferentes extratos de hortali?as do tipo A e B

摘要

Total copper content analysed in samples of A and B vegetables through atomic flame absorption spectroscopy and sequential extraction were performed by using the following extractants: CaCl21.0M solution; acetic acid 0.1M; acetic acic 0.5M / ammonium acetate 5% solution [pH = 5.0]; NaOH 0.1M solution and HCl 0.5M solution. For evaluation of the results Grubbs test and Student test were used. On average 25.4% of total copper were extracted in CaCl2 1.0M solution with a maximum extraction of 50.5% and a minimum of 8.3%. On average 14.8% of the total amount of copper, a maximum of 32.6% and a minimum of 64% were extracted in acetic acid 0.1M solution. Using acetic acid 0.5M / ammonum acetate 5% [pH = 5.0] solution, the minimum extracted was 6.2% and the maximum 27.6% with 13.75% as average. The less effective extractant was NaOH 0.1M (10.5%) and HCl 0.5M extractant which had anaverage of 12.6% of extraction. The copper extracted was present at least in of six different chemical species.