Determination of thiol compounds in Pisum sativum exposed to lead and cadmium ions by HPLC with post-column derivatization

HPLC procedure for determination of peptides synthesized from glutathione in the presence of some heavy metals has been proposed. Thiol compounds were identified by post-column derivatization of sulfhydryl groups with Ellman's reagent: 5,5'-dithiobis(2-nitrobenzoic acid). The proposed method has been applied to pea plants (Pisum sativum) grown in the Hoagland solution containing cadmium and lead ions. In this research we have studies accumulation of heavy metals in different parts of pea plants and concentrations of thiol compounds, like glutathione and phytochelatins, synthesized by plants treated with Cd and Pb. Pea plants were exposed to different concentrations of cadmium chloride and lead nitrate (0.1 mmol L-1 Cd, 0.5 mmol L-1 Pb and 0.1 mmol L-1 Pb with 0. 1 mmol L-1 Cd (Pb/Cd)) for 18 days. Plant material was collected after 1, 2, 3, 4, 7, 14, and 18 days of the treatment with heavy metals. We have observed the influence of Cd on Pb uptake. The presence of Cd in a nutrient solution inhibited Pb accumulation in pea roots. Cd was the most effective activator of phytochelatin synthesis in roots, but any thiol compound except from glutathione was detected in shoots and leaves.