Determination of 1-naphthol and 2-naphthol from environmental waters by magnetic solid phase extraction with Fe@MgAl-layered double hydroxides nanoparticles as the adsorbents prior to high performance liquid chromatography

Magnetic Fe@MgAl-layered double hydroxides (MgAl-LDHs) composite was firstly synthesized by coating MgAl-layered double hydroxides on the surface of the dispersed nanoscale zero valent irons with co-precipitation method and characterized by transmission electron microscopy and X-ray diffraction techniques. The synthesized Fe@MgAl-LDHs nanoparticles were investigated for magnetic solid phase extraction (MSPE) of 1-naphthol and 2-naphthol from the water samples. The elutent containing 1-naphthol and 2-naphthol was analyzed by high performance liquid chromatography with variable wavelength detection (HPLC–UV). Under optimal conditions, there is good linear relationship between the concentration and the peak area in the range of 0.5–200   μg   L −1 with the correlation coefficients ( r 2 ) above 0.998 for 1-naphthol and 2-naphthol. The limits of detection were 0.22   μg   L −1 and 0.19   μg   L −1 for 1-naphthol and 2-naphthol, respectively, and precisions were both below 2.5% ( n   =   6). The real water analysis demonstrated that the spiked recoveries were in the range of 79.2–80.9% ( n   =   3). All these results indicated that the developed MSPE–HPLC–UV method was proved to be an efficient tool for the analysis of naphthols.