Magnetic dispersive solid-phase extraction for the determination of three different glycosides in the Kang'ai injection

Abstract

In this work, the content of flavonoid glycosides and astragalosides in a Chinese medicine injection was determined by using the magnetic dispersive solid phase extraction method coupled with high performance liquid chromatography with an evaporative light-scattering detector (HPLC/ELSD). Multi-walled carbon nanotubes (MWCNTs) modified by Fe3O4 nanoparticles obtained in a one-step synthetic procedure, were used as a sorbent to conveniently remove the analytes from water. Single factor experiments were performed to investigate the factors that affected the extraction efficiency, such as the hydroxyl content of the modified MWCNTs, the amount of sorbent, the type of elution solvent, the volume of elution solvent, sample pH and salting-out effect. Under the appropriate optimal conditions, the limits of detection (LODs) and limits of quantification (LOQs) for the three glycosides ranged from 0.16 μg/mL to 0.60 μg/mL and 0.58 μg/mL to 1.24 μg/mL, respectively. Moreover, the intra- and interday precision ranged from 1.9% to 2.9% and 2.4% to 4.5%, respectively. Meanwhile, the recoveries of spiked samples were measured, which ranged from 91.1% to 96.2% with relative standard deviations (RSDs) ranging from 2.8% to 3.8%. Accordingly, the application of the proposed method for the analysis of Chinese medicine injection samples offered several advantages: an acceptable precision, low LODs and good recoveries. This work might provide a research basis for the quality control of Chinese medicine injections and the further study of the Kang'ai injection.