Dispersive micro-solid phase extraction of aromatic amines based on an efficient sorbent made from poly(1,8-diaminonaphtalen) and magnetic multiwalled carbon nanotubes composite

In this work, the extraction of aromatic amines with an efficient magnetic multiwalled carbon nanotubes/Fe₃O₄@Poly(1,8-diaminonaphtalen) (MWCNTs/Fe₃O₄@PDAN) composite followed by HPLC-DAD was presented. Imprimis, the comparison among different magnetic nanosorbents including Fe₃O₄, MWCNTs/Fe₃O₄, Fe₃O₄@PDAN and MWCNTs/Fe₃O₄@PDAN was conducted. The obtained results, exhibited that the MWCNTs/Fe₃O₄@PDAN composite has the highest extraction efficiency for target analytes (3-nitroaniline, 4-chloroaniline, 4-bromoaniline and 3,4-dichloroaniline). This sorbent was characterized by Fourier transform infrared spectroscopy, X-ray dispersive spectroscopy, thermogravimetry analysis, scanning electron microscopy, transition electron microscopy, vibrating sample magnetometry and X-ray diffraction. Design of experiment approach was applied to find out the optimal experimental conditions. The optimal extraction conditions were: pH of the sample, 10; sorbent amount, 10mg; sorption time, 15min; salt concentration, 10% w/w; type and volume of the eluent, 0.01molL^-1 HCl in acetonitrile, 145μL; elution time; 2min. Under the optimal extraction conditions detection limits and linear dynamic ranges were achieved in the range of 0.1-0.25μgL^-1 and 0.25-500μgL^-1, respectively. The percent of extraction recovery and relative standard deviations (n=5) were in the range of 31.2-82.8% and 3.4-5.6%, respectively. Finally, the applicability of the method was successfully confirmed by the extraction and determination of target analytes in various water samples.