Preconcentration and determination of lead and cadmium in water samples with a MnO₂ coated carbon nanotubes by using ETAAS

• Published in: Desalination Vol. 278; no. 1-3; pp. 65 - 69
• Main Authors: Yang, Binwu, Gong, Qiaojuan, Zhao, Liping, Sun, Hong, Ren, Ningning, Qin, Jinxin, Xu, Jie, Yang, Haiying
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.09.2011; Elsevier
• Subjects: Applied sciences; atomic absorption spectrometry; Cadmium; carbon nanotubes; Chemical engineering; desalination; detection limit; Exact sciences and technology; Extraction; Flow rate; Heat and mass transfer. Packings, plates; ions; lead; manganese dioxide; Nanomaterials; Nanostructure; nitric acid; Pollution; Separation; Standard deviation; trace elements; Solid phase extraction; Cadmium; MnO; Trace element; Detection limit; ETAAS; Reference material; Preconcentration; pH; Lead; MWCNTs; Packed column; Atomic absorption spectrometry
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/j.desal.2011.05.010

A procedure for separation and preconcentration trace amount of Pb(II) and Cd (II) by nano-sized manganese dioxide functionalized multi-wall carbon nanotubes (MnO₂/MWCNTs) packed column has been proposed. Various influencing parameters on the separation and preconcentration of trace metals, such as pH, flow rate, concentration of eluent, sample volume and interference ions, were studied. Under the optimized conditions (pH 6, flow rate 2.5mLmin⁻¹), Pb(II) and Cd (II) were retained on the column, then quantitatively eluted by 1.5mL 1.5molL⁻¹ nitric acid solution and determined by electrothermal atomic absorption spectroscopy (ETAAS). The detection Limits of Pb(II) and Cd(II) for an extraction of 5.0mL water sample were 4.4 and 1.5ngL⁻¹, respectively. The relative standard deviations (R.S.D.) were 3.2% and 2.5% for Pb(II) and Cd(II), respectively. The optimized method was successfully applied to the determination of Pb(II) and Cd(II) in certified reference materials and real water samples.