Simultaneous Preconcentration of Copper and Cadmium by Dispersive Liquid-Liquid Microextraction Using N,N'-Bis (2-Hydroxy-5-Bromo-Benzyl)1,2 Diaminopropane and Their Determination by Flame Atomic Absorption Spectrometry.

In the present study, the simultaneous preconcentration of copper and cadmium based on dispersive liquid-liquid microextraction as a prior step to their determination using flame atomic absorption spectrometry was developed. Carbon tetrachloride and N,N'-bis(2-hydroxy-5-bromo-benzyl)1,2 diaminopropane were used as the extraction solvent and chelating ligand, respectively. Some parameters that influence the extraction efficiency-e.g., sample pH, volume of extraction solvent (carbon tetrachloride), concentration of the chelating ligand, effect of salt addition, and sample volume-were investigated and optimized. With a preconcentration factor of 10, the LODs (3σ) for Cd and Cu were 0.69 and 1.98 μg/L, respectively. The accuracy of the developed method was evaluated by analyzing SLRS-5 river water and SRM 1573a tomato leaves certified reference materials. Results obtained were in good agreement with the certified values. The proposed method was successfully applied to river water, seawater, and black tea samples. Good spike recoveries, varying within the range of 97.5 to 116.9%, confirmed the good performance of the method in real sample analysis.