Synthesis, characterization and application of a polyindole coated magnetic porous carbon nanoadsorbent for extraction and determination of toxic aromatic amines

In this research, a polyindole coated magnetic porous carbon (MPC@PIN) nanoadsorbent was synthesized and applied to the extraction of toxic aromatic amines from divers real water. The MPC was derived from MIL-53(Fe) as a metal–organic framework (MOF) source by calcination of the MOF under an inert atmosphere. After that, the functionalization process was performed by the polymerization of indole on the surface of the MPC. The synthesized nanoadsorbent (MPC@PIN) was characterized by various methods such as Fourier transform-infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and vibrating sample magnetometry (VSM). Separation and determination of the target analytes was performed by HPLC-photodiode array (PDA) detection system. The extraction performance of MIL-53(Fe), MPC, and MPC@PIN was compared toward the target analytes, and the results exhibit the best extraction efficiency for the MPC@PIN. After optimization of the affecting parameters, LODs and linear ranges were 0.05–0.2 µg/L and 0.15–400 µg/L, respectively. Precision (n = 3) of the method as intra-day RSD, and inter-day RSD values were obtained in the range of 3.5–8.2%, and 5.8–12.3%, respectively. Finally, the method applicability was affirmed by analyzing various water samples, satisfactorily. To prepare spiked water samples, a small volume of the AAs standard solution was added to each sample, and then the spiked sample was subjected to the MSPE process.