Ligandless dispersive liquid–liquid microextraction combined with syringe to syringe back extraction for the determination of lead in water samples by flame atomic absorption spectrometry
Abstract
Ligandless dispersive liquid–liquid microextraction (DLLME) combined with syringe to syringe back extraction was applied for the extraction and preconcentration of Pb prior to analysis by flame atomic absorption spectrometry. In DLLME, Pb was extracted into a small volume of 1,2-dichlorobenzene. After separation of the organic phase by centrifugation, Pb enriched in the 1,2-dichlorobenzene phase was back extracted into 80 μL of 0.1 mol L−1 HNO3 using two syringes. The experimental parameters affecting the extraction efficiency of Pb such as the extraction and disperser solvent type and volume, pH, ultrasound extraction time, HNO3 solution volume of back extraction and number of injections were investigated and optimized. Under the optimal conditions, satisfactory linearity, sensitivity and reproducibility were obtained. Finally, the applicability of this newly developed method was investigated for the analysis of Pb in real water samples.