AAS Determination of Copper in Water After Enrichment by Adsorption on Bipyridylamine-Functionalized Multi-wall Carbon Nanotubes

The intermediate of acyl-chlorinated multi-wall carbon nanotubes (MWCNT′s) was prepared by the modification reaction of carboxylated MWCNT′s with SOCl2,and the object material,2,2′-bipyridylamine functionalized MWCNT′s (MWCNT-Dipy) were prepared by the reaction with 2,2′-bipyridylamine in DMF medium.Structure of the MWCNT-Dipy and its adsorptivity toward Cu2+-ion in water were studied in detail.In an aqueous medium of pH 6,the MWCNT-Dipy behaved to adsorb Cu2+-ion strongly and equilibrium of adsorption was achieved by shaking with MWCNT-Dipy for 15 min,and the adsorptive capacity of Cu2+-ion at equilibrium was 3.2 mg·g-1.The Cu2+-ion adsorbed on the surface of MWCNT-Dipy was completed desorbed by shaking with 6 mL of 1.0 mol·L-1 HCl solution,in which the copper content was determined by AAS.Recovery was tested on samples of pure water by standard addition method,giving results of recovery in the range of 94.3%-96.9%.