Aluminum separation from drinking water and serum samples based on djenkolic acid immobilized on the multi walled carbon nanotubes by ultrasound-assisted dispersive micro solid phase extraction

Abstract

A new method for aluminum extraction from drinking water and human serum samples was used by djenkolic acid (DJKA) immobilized on multi walled carbon nanotubes (MWCNTs-DJKA). By procedure, the mixture of 25 mg of MWCNTs-DJKA sorbent and hydrophobic ionic liquid ([OMIM][PF6]) were dispersed with ultrasonic bath in 10 mL of drinking water and serum samples for 10 min at pH=5. The aluminum ions were extracted based on MWCNTs-DJKA sorbent in liquid phase by ultrasound-assisted dispersive micro solid phase extraction (USA-D-μ-SPE). After centrifuging, the Al (III) was separated from liquid phase by ionic liquid phase in bottom of centrifuge PVC tube. Finally, the Al (III) were back-extracted from sorbent/IL in acidic pH and measured by electrothermal atomic absorption spectrometry (ET-AAS). In optimized study, LOD, LOQ, the linear range, the working range and the enrichment factor were obtained 0.1 µg L−1, 0.3 µg L−1, 0.3-12.8 µg L−1, 0.3-30.7 µg L−1 and 9.92, respectively (RSD< 5%). The adsorption capacity of the MWCNTs-DJKA sorbent was obtained in batch system. Based on proposed procedure, the mean concentrations of aluminum in drinking waters and serum samples were lower than world health organization (WHO) and American conference of governmental industrial hygienists (ACGIH) references. The method was validated by spiking samples and standard reference materials (SRM) in water and human biological samples.