Fabrication and characterization of SiO2@Fe3O4@nanodiamonds for vortex-assisted magnetic solid-phase extraction of lead in cigarette samples prior to FAAS detection

摘要

A novel, speed and accurate vortex-assisted magnetic solid-phase extraction procedure for separation-preconcentration and flame atomic absorption spectrometric determination of lead at trace levels has been proposed. Silica-coated magnetic nanodiamonds (SiO2@MNDs) as magnetic solid-phase extractor were fabricated and characterized by Fourier transform infrared spectroscopy, X-ray diffraction spectrometry and scanning electron microscopy. Pb(II) could be easily separated from the aqueous solution on the SiO2@MNDs by using a neodymium magnet. Analytical factors affecting the recoveries of Pb(II) such as pH, adsorbent amount, type and volume of eluent and sample volume were optimized. The preconcentration factor, the precision (RSD %, n = 5), the limit of detection and the limit of quantification were 5, 5.3%, 40.8 and 135 mu g L-1, respectively. The effects of matrix ions have been investigated. The presented extraction method has been applied for the determination of lead in cigarette samples and Bush Branches and Leaves certified reference material. Quantitative recoveries changing from 94 to 106% were obtained for accuracy studies.