INFLUENCES OF LEAD CONTAMINATION AND COMPLEXING AGENTS ON THE METAL UPTAKE OF CUCUMBER

Cucumber plants were grown in six different nutrient solutions with va rying compounds of iron (FeCl3, Fe-citrate, or Fe-EDTA) with and witho ut addition of lead. The concentrations of B, Ca, Cu, Fe, Mg, Mn, Ni, Pb, and Zn in the third leaves of the plants were determined by induct ively coupled plasma-atomic emission spectrometry after microwave-assi sted acidic digestion of the dried samples. In the presence of EDTA le ad contamination results in growth stimulation and considerably higher uptake of Cu and Ni. However, addition of lead to the nutrient soluti ons containing citrate or chloride leads to a significant reduction of growth and a higher uptake of Ca, Mg, Zn, and Ni. The magnitude of le ad effect is definitely stronger in presence of citrate. (C) 1995 Acad emic Press, Inc.