title: Selective solid-phase extraction and analysis of trace-level Cr(III), Fe(III), Pb(II), and Mn(II) Ions in wastewater using diethylenetriamine-functionalized carbon nanotubes dispersed in graphene oxide colloids.
abstract: Multi-walled carbon nanotubes (MCNTs) were dispersed in graphene oxide (GO) colloids to be further functionalized with diethylenetriamine (DETA), resulting in GO-MCNTs-DETA nanocomposites for the solid-phase extraction and analysis of Cr(III), Fe(III), Pb(II), and Mn(II) ions at the trace levels in wastewater. Inductively coupled plasma optical emission spectrometry (ICP-OES) indicates that this new solid-phase sorbent could facilitate the maximum static adsorption capacities of 5.4, 13.8, 6.6 and 9.5 mg g(-1) for Cr(III), Fe(III), Pb(II), and Mn(II) ions, respectively, showing the adsorption capacity up to 95% within about 30 min. Moreover, the detection limits of the GO-MCNTs-DETA-based analysis method were found to be 0.16, 0.50, 0.24 and 0.38 ng mL(-1) for Cr(III), Fe(III), Pb(II), and Mn(II) ions, respectively, with the relative standard deviation of lower than 3.0% (n=5). Importantly, common coexisting ions showed no significant interference on the separation and pre-concentration of these heavy metal ions at pH 4.0. Subsequently, the GO-MCNTs-DETA sorbent was successfully employed for the separation and analysis of trace-level Cr(III), Fe(III), Pb(II), and Mn(II) ions in wastewater samples yielding 75-folds concentration factors.
authors.affiliation: Shandong Province Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu City 273165, PR China.
authors.forename: Xiangbing
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Jining Bureau Quality and Technical supervision, Shandong 272000, PR China.
authors.forename: Yuemei
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Department of Chemistry, Lanzhou University, Lanzhou 730000, PR China.
authors.forename: Xijun
authors.initials: X
authors.lastname: Chang
authors.affiliation: Shandong Province Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu City 273165, PR China. Electronic address: huawangqfnu@126.com.
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
keywords: Diethylenetriamine; Graphene oxide; Heavy metal ions; Inductively coupled plasma optical emission spectrometry; Multi-walled carbon nanotubes; Solid-phase extraction