SOME METALS (Fe, Mn, Zn, Cu, Pb, Cd) CONTENTS IN VEGETABLES FROM A NONPOLLUTED PLAIN AREA OF CENAD-BANAT (ROMANIA)

摘要

This paper presents original studies about the occurrence of some heavy metals (Fe, Mn, Zn, Cu, Pb and Cd) in soil and different vegetables (pepper, cucumbers, tomatoes. eggplants, green beans, cauliflower, cabbage, dill-leaves, parsley-leaves and roots, celery-leaves and roots, onion, garlic and potatoes) cultivated in nonpolluted plain area in Cenad-Banat County. The accurate determination of toxic heavy metals in vegetables is of importance because of the toxicity of these elements and their compounds. Total heavy metals in vegetable samples were analyzed after wet digestion with mineral acid, and in the soils they were analyzed after digestion in aqua regia. All metals were analyzed using high-resolution continuum source spectrometer ContrAA-300, Analytik-Jena in the acetylene flame (99.99 % purity). In comparison with official imposed limited the average values for heavy metals contents in soil are in the normally interval for Zn, Cu and Pb , for Cd the limit is exceeded, but under warning threshold. The smaller content of total heavy metals (around 2.5 ppm) was identified in cucumbers, cauliflower and cabbage. In pepper, tomatoes, eggplants, green beans, onion and potatoes the total content of heavy metals are between 3-6 ppm. In root of carrot, celery and parsley the total content is between 3-7 ppm with maximum in parsley root. The highest values were identified in leaves of parsley, dill, celery and garlic. For all soil and vegetables samples the average concentrations of all analyzed metals are lower than the limits established by the present Romanian legislation.