Dispersive liquid-liquid microextraction for the preconcentration and spectrophotometric determination of copper(II) in blood serum sample using sodium diethyldithiocarbamate as the complexing agent

Abstract

 A dispersive liquid-liquid microextraction (DLLME) process based on the complexation reaction of Cu(II) with diethyldithiocarbamate (DDTC) from aqueous solutions was investigated. The effect of various experimental parameters in the extraction such as, dispersive solvent, extracting solvent, the volume of extraction and disperser solvent, pH of the aqueous solution, ionic strength and extraction time were optimized using one variable at a time method, and the analytical charactristics of the method were obtained. Under the optimum conditions the calibration graph was linear over the range 0.01 to 0.1 μg mL-1 of Cu(II) ion with a correlation coefficient of 0.994. The limit of detection (S/N = 3) was 8.6 × 10-3 μg mL-1. Relative standard deviation (RSD) for 7 replicate determinations of 0.08 μg mL-1 Cu(II) was 3.3%. In this work, the concentration factor of 20 and also the improvement factor of 33 were reached. The interference effect of some anions and cations was also tested. The extraction method has been successfully applied to the determination of copper in human blood serum sample.