Bioaccumulating plants: monitoring of heavy metals in leaves and roots of wheat and sunflower using a fast and indirect detection by open-tubular capillary electrochromatography

Abstract

Human activity such as industrial development, urbanization and intensive agriculture, has led to extensive environmental problems. Since heavy metals are mobile and easily absorbed by plants in the environment, they are transmitted to the human body through nourishment. Metal-accumulating plants, such Triticum species and Helianthus annuus L., can accumulate high concentrations of heavy metals in both leaves and roots from polluted soil and waters. For the determination of these elements we used CZE with indirect detection. This technique require the dissolution of the sample, with this aim three digestion procedures were applied. The best results were obtained in batch using a mixture of HNO3+HCl. The detection was performed at 214 nm; the voltage was set at 25 kV. Samples were pressure-injected at the cathodic side at 0.5 psi for 10 seconds. The background electrolyte (BGE) used consisted of 6 mM imidazole, pH 4.0 adjusted with 1 M acetic acid. The proposed method allows the rapid determination of heavy metals in natural products. It was recently demonstrated that MW-assisted acid treatment with H2O2 could be used satisfactorily for sample clean-up technique prior to CE determination of various metals species. This methods have a great potential to be applied in phytoremediation in which the use of green plants help to remove contaminants from soil and groundwater.