مشخصات پژوهش

Lead is a toxic element and has deleterious effects on multiple organs of the human body. So, much interest and effort have been devoted to its determination in biological fluids [1]. Flame atomic absorption spectrometry (FAAS) is commonly used for this purpose. However, in many cases due to the concentrations lower than detection limits and/or the interferences from the matrix of biological samples, pre-concentration and/or separation processes are inevitable [2]. Microextraction techniques are very useful and popular for the pre-concentration and separation of organic and inorganic analytes at trace levels due to their advantages like simple procedure, high extraction efficiency and low consumption of toxic organic solvents. In this study, a recently reported technique namely air-assisted liquid-liquid microextraction (AALLME) [3] was investigated for extraction and pre-concentration of trace amounts of Pb2+ ions before determination of it by FAAS. O, O- diethyl dithiophosphoric acid was used as a chelating agent to form a hydrophobic complex. AALLME is similar to dispersive liquid-liquid microextraction but in this method there is no need to use a disperser solvent. Some effective parameters on the microextraction and the complex formation were investigated including extraction solvent type and its volume, pH, concentration of the chelating agent and extraction time. Finally, the proposed method was successfully utilized for the pre-concentration and determination of Pb2+ ions from different samples to achieve high EFs extraction recoveries nearly 100%, and low detection limits.