Speciation analysis of Mn(II)/Mn(VII) using Fe3O4@ionic liquids-β-cyclodextrin polymer magnetic solid phase extraction coupled with ICP-OES

• A novel Fe3O4@ILs-β-CDCP-MSPE-ICP-OES for the speciation of Mn(II)/Mn(VII) was developed.
• The separation of Mn(VII) and Mn(II) can be realized by selected the proper pH.
• Mn(VII) could be extracted by Fe3O4@ILs-β-CDCP at the pH value of 6.0.
• Mn(II) content was calculated by subtraction of Mn(VII) from the total Mn.
• The proposed procedure was applied to the speciation of Mn(II)/Mn(VII) in environmental water samples.

Ionic liquids-β-cyclodextrin polymer (ILs-β-CDCP) was attached on Fe3O4 nanoparticles to prepare magnetic solid phase extraction agent (Fe3O4@ILs-β-CDCP). The properties and morphology of Fe3O4@ILs-β-CDCP were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction(XRD), size distribution and magnetic analysis. A new method of magnetic solid phase extraction (MSPE) coupled to ICP-OES for the speciation of Mn(II)/Mn(VII) in water samples was established. The results showed that Mn(VII) and total manganese [Mn(II)+Mn(VII)] were quantitatively extracted after adjusting aqueous sample solution to pH 6.0 and 10.0, respectively. Mn(II) was calculated by subtraction of Mn(VII) from total manganese. Fe3O4@ILs-β-CDCP showed a higher adsorption capacity toward Mn(II) and Mn(VII). Several factors, such as the pH value, extraction temperature and sample volume, were optimized to achieve the best extraction efficiency. Moreover, the adsorption ability of Fe3O4@ILs-β-CDCP would not be significantly lower after reusing of 10 times. The accuracy of the developed method was confirmed by analyzing certified reference materials (GSB 07-1189-2000), and by spiking spring water, city water and lake water samples.

pH is one of the main factors influencing the adsorption Fe3O4@ILs-β-CDCP behavior of metal ions. The separation of Mn(VII) and Mn(II) can be realized by selected the proper pH. Mn(VII) could be fully extracted at the pH 6.0. Mn(II) and Mn(VII) could be adsorbed at the pH 10.0.Figure optionsDownload as PowerPoint slide