title: Schiff base-chitosan grafted multiwalled carbon nanotubes as a novel solid-phase extraction adsorbent for determination of heavy metal by ICP-MS.
abstract: A novel Schiff base-chitosan-grafted multiwalled carbon nanotubes (S-CS-MWCNTs) solid-phase extraction adsorbent was synthesized by covalently grafting a Schiff base-chitosan (S-CS) onto the surfaces of oxidized MWCNTs. The adsorbent was characterized by Fourier-transform infrared spectroscopy, transmission electron microscopy, and thermal gravimetric analysis. The results showed that S-CS was successfully grafted onto the surfaces of MWCNTs. A method was developed for the determination of heavy metals, namely V(V), Cr(VI), Cu(II), As(V) and Pb(II) in biological and environmental samples by inductively coupled plasma mass spectrometry coupled with preconcentration with S-CS-MWCNTs. The parameters influencing preconcentration of target ions, such as the pH of the sample solution, the flow rate of sample loading, the eluent concentration, and eluent volume, were investigated and optimized. Under the optimal conditions, the enrichment factors of V(V), Cr(VI), Cu(II), As(V), and Pb(II) reached 111, 95, 60, 52, and 128, respectively, and the detection limits were as low as 1.3-3.8 ng L(-1). The developed method was successfully applied to the determination of trace-metal ions in herring, spinach, river water, and tap water with good recoveries ranging from 91.0% to 105.0%.
authors.affiliation: Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin 300457, China.
authors.forename: Bingye
authors.initials: B
authors.lastname: Dai
authors.forename: Meirong
authors.initials: M
authors.lastname: Cao
authors.forename: Guozhen
authors.initials: G
authors.lastname: Fang
authors.forename: Bing
authors.initials: B
authors.lastname: Liu
authors.forename: Xv
authors.initials: X
authors.lastname: Dong
authors.forename: Mingfei
authors.initials: M
authors.lastname: Pan
authors.forename: Shuo
authors.initials: S
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D048271:Chitosan / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry / Q000379:methods*; D019216:Metals, Heavy / Q000032:analysis*; D046529:Microscopy, Electron, Transmission; D037742:Nanotubes, Carbon; D012545:Schiff Bases / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000295:instrumentation*; D017550:Spectroscopy, Fourier Transform Infrared; D013818:Thermogravimetry
chemical_list: D019216:Metals, Heavy; D037742:Nanotubes, Carbon; D012545:Schiff Bases; D048271:Chitosan