Supramolecular solvent-based dispersive liquid–liquid microextraction of copper from water and hair samples

Abstract

A supramolecular solvent based dispersive liquid–liquid microextraction (SM-DLLME) procedure has been established for the separation and preconcentration of Cu(II) before its determination by microsampling flame atomic absorption spectrometry. The proposed method involves the use of a supramolecular solvent in which reverse micelles of 1-decanol are dispersed in tetrahydrofuran. The Cu(II)–pyrrolidinedithiocarbamate complex was formed to increase interactions with the supramolecular phase at pH 6. After the supramolecular solvent was added to the medium, the formation of micelles of nano and molecular size was observed in an ultrasonic bath. The solution was centrifuged, and the metal complex formed was extracted into the supramolecular solvent phase. Some analytical parameters that are important in the experiment were examined in detail. The detection limit (LOD), the quantification limit (LOQ) and the relative standard deviation (RSD) of the developed method were found to be 0.11 μg L⁻¹, 0.34 μg L⁻¹ and 2.2%, respectively. The preconcentration factor was 60. Addition/recovery studies were also performed in water and human hair samples. The accuracy of the proposed method was assessed by analyzing certified reference materials. The procedure was applied for the determination of copper in water and hair samples.