Influences of Lead Contamination and Complexing Agents on the Metal Uptake of Cucumber

Cucumber plants were grown in six different nutrient solutions with varying compounds of iron (FeCl3, Fe-citrate, or Fe-EDTA) with and without 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 inductively coupled plasma-atomic emission spectrometry after microwave-assisted acidic digestion of the dried samples. In the presence of EDTA lead contamination results in growth stimulation and considerably higher uptake of Cu and Ni. However, addition of lead to the nutrient solutions containing citrate or chloride leads to a significant reduction of growth and a higher uptake of Ca, Mg, Zn, and Ni. The magnitude of lead effect is definitely stronger in presence of citrate.