Preparation and characterization of magnetic Wells-Dawson heteropoly acid nanoparticles for magnetic solid-phase extraction of aromatic amines in water samples.

In this work, aminopropyl modified silica-coated magnetite nanoparticles with Wells-Dawson heteropoly acid (PWFe@APSCMNPs) was first synthesized and underwent highly efficient magnetic solid-phase extraction (MSPE) of aromatic amines from aqueous samples. The resulted nanomaterials were characterized with different physicochemical techniques such as Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). Aniline, N,N-dimethylaniline, o-toluidine and 3-chloroaniline were selected as target compounds. The sample quantification was carried out using gas chromatography-flame ionization detector (GC-FID). Under optimal working conditions, the developed method showed good linearity (R>0.9912) in the range of 0.01-100ngmL. The method displays detection limits (at an S/N ration of 3) in the range from 0.003 to 0.01ngmL, and the limits of quantification (at an S/N ratio of 10) are between 0.01 and 0.04ngmL. The enrichment factors (EFs) were in the range of 75-113. Relative standard deviations (RSDs) are 4.8-8.3%. The applicability of the developed method was examined by analyzing different water samples (river water, tap water, well water and wastewater) and the relative recovery values for the spiked water samples were found to be in the range of 90.7-99.8%.