Adenine-coated magnetic multiwalled carbon nanotubes for the selective extraction of aristolochic acids based on multiple interactions

A method is described for the functionalization of magnetic carbon nanotubes to recognize aristolochic acid I and II. 3-Glycidyloxypropyltrimethoxysilane was used as a coupling agent to immobilize adenine on a solid support. The morphology and structure of adenine-coated magnetic carbon nanotubes was investigated using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and a vibrating sample magnetometer (VSM). The adsorption performance of the adeninecoated magnetic carbon nanotubes was evaluated via adsorption isotherms, the kinetics and selectivity tests. The adsorption capacity of the adenine-functionalized sorbent for aristolochic acid. was determined to be 24.5 mu g mg(-1). By combining magnetic solid phase extraction with HPLC detection, a method was developed to enrich and detect aristolochic acids used in traditional Chinese medicine. A satisfactory recovery (92.7 - 97.5% for aristolochic acid. and 92.6 - 99.4% for aristolochic acid.) and an acceptable relative standard deviation (<4.0%) were obtained. (c) 2020 Elsevier B.V. All rights reserved.