Magnetic triptycene-based covalent triazine frameworks for the efficient extraction of anthraquinones in slimming tea followed by UHPLC-FLD detection

A magnetic triptycene-based CTF (M-CTF-TPC) has been synthesized by a covalent bonding method, and was characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and nitrogen adsorption-desorption isotherms. The M-CTF-TPC exhibits the properties of high porosity, large surface area and strong magnetism. The extraction conditions were optimized, and a novel method coupled with magnetic solid phase extraction (MSPE) and ultra-performance liquid chromatographic analysis-fluorescence detection (UHPLC-FLD) was established the analysis of anthraquinones. The enrichment factors for the proposed method were 72.8–88.6, and the limits of detection for the five anthraquinones were found to be in the range of 0.010–0.077 μg g−1. The proposed method was applied to the determination of anthraquinones in slimming tea with satisfactory recoveries (94.5–105.4%) and lower RSDs (3.0–5.8%), demonstrating its excellent accuracy. These results suggest that the promising potential of M-CTF-TPC as sorbent in sample pretreatment.