Sensitive determination of bisphenol A, 4-nonylphenol and 4-octylphenol by magnetic solid phase extraction with Fe@MgAl-LDH magnetic nanoparticles from environmental water samples

Mg-Al-layered double hydroxide (Mg-Al-LDH) modified nanoscale zero-valent iron (NZVI) (Fe@MgAl-LDH) was firstly synthesized and characterized by several techniques. The results showed that the layered double hydroxides were coated on the surface of nanoscale zero-valent iron particles. This new material exhibited good adsorption for bisphenol A, 4-octylphenol and 4-nonylphenol from water samples. Based on these, a sensitive method was developed for the extraction and preconcentration of bisphenol A, 4-octylphenol and 4-nonylphenol using magnetic Fe@MgAl-LDH nanoparticles as the solid phase extraction adsorbents prior to high performance liquid chromatography coupled with variable wavelength detection. Under the optimal conditions, linear responses were achieved in the range of 0.5-200 μg L−1 with the correlation coefficients (r) above 0.999. The detection limits of three analytes were in the range of 0.24-0.34 μg L−1, and precisions were all below 2.5% (n = 6). The proposed method was evaluated with real water samples and the excellent spiked recoveries in the range of 96.0-99.3% were achieved.