Application of ultrasonic assisted dispersive liquid phase micro extraction combined with dispersive micro solid phase extraction for simultaneous pre-concentration and trace detection of lead and cadmium ions

چکیده مقاله

Background: Environmental contamination with heavy metals as a worldwide concern menace the human life. Heavy metals are natural components of the seawaters and a large amount of them enter naturally to the rivers and ground waters via various ways such as erosion of mines, dust particles, and volcanic activity. Regional increase of these metals by human-induced industrial processes such as industrial wastes from factories, textile, mining, and other metal smelting process are the major concern [1-3]. Methods: In the present method a hybrid extraction method was utilized for simultaneous detection of cadmium and lead ions. In the first step a liquid phase micro-extraction based on dispersion of organic solvent was used for the fast extraction of complexed ions with dithizone from aqueous solution and in the next step the extraction organic solvent was effectively collected from the solution without any requirement to centrifuge step by using C18-magnetic nanoparticles. Pre-concentrated lead and cadmium ions was monitored by GFAAS at ng L-1. Results: Optimized data for parameters that obtained by Box-Behnken design were: sample’s pH: 5.7, ligand/metal concentration ratio: 8, magnetic based sorbent amount: 15 mg and 1-octanol volume: 26 microliter. Relative standard deviation by the hybrid extraction method was observed to be < 6 % for both ions and method detection limit for cadmium and lead ions was 2 ng L-1 and 5 ng L-1, respectively. Conclusion: The findings of characterization tests of the introduced sample preparation method proved that the developed hybrid extraction method is extremely effective for preconcentration of cadmium and lead cations.