Adsorptive separation of copper, nickel, lead, zinc and cadmium from aqueous solution using MWCNTs impregnated with D2EHPA and prior to their determination by FAAS: Kinetic and equilibrium studies

Trace metal ions in aqueous samples may be separated and preconcentrated by solid phase extraction (SPE) prior to their determination by flame atomic absorption spectrometry (FAAS). The trace amounts of heavy metals can form complex with D2EHPA - MWCNTs. The quantitative adsorption was at pH 5.0 with a flow rate of 2 mL(-1). The adsorbed metal ions can be eluted with 2.0 mol L-1 HNO3. The highest enrichment factor was 25. The thermodynamic parameter (G) revealed that the adsorption was spontaneous. The procedure was applied to the determination of copper, nickel, lead, zinc and cadmium in laboratory water, well water and electroplating wastewater samples.