Magnetic porous carbon derived from NH2-MIL-101(Fe) as an adsorbent for the magnetic solid-phase extraction of anthraquinones

A magnetic porous carbon NH2-MIL-101-C was synthesized through a one-step carbonization process using NH2-MIL-101(Fe) as the precursor. The morphology, structure, magnetic behavior, and porosity of the as-prepared NH2-MIL-101-C were characterized. The results show that NH2-MIL-101-C has a high Brunauer-Emmett-Teller surface area (213.7 m(2)/g), a large pore volume (0.2 m(3)/g), and a good magnetic property (23.4 emu/g). The NH2-MIL-101-C was first used as a magnetic solid-phase extraction adsorbent for the extraction of five anthraquinones from rhubarb. The main parameters that will affect the extraction efficiency were investigated. Under the optimized conditions, good linearity for the five anthraquinones was obtained with the R-2 higher than 0.9910. The limits of detection and limits of quantitation for the analytes are 0.018-0.042 and 0.050-0.140 mu g/mL, respectively.