A Simple and Sensitive Dispersive Micro-Solid-Phase Extraction Coupled with High-Performance Liquid Chromatography for Quantification of Honokiol and Magnolol in Complex Matrices

Background: Honokiol and magnolol were considered as markers for the analysis of Cortex Magnoliae Officinalis, its related Chinese Patent Medicines and their metabolites. However, the determination of these two analytes in a water-soluble sample is difficult and therefore requires a more efficient method.

Objective: To develop a sensitive method for the determination of honokiol and magnolol in a water-soluble sample for better quality control of Cortex Magnoliae Officinalis and its related Chinese Patent Medicines.

Method: In this work, a combination of dispersive micro-solid-phase extraction (DMSPE) and high-performance liquid chromatography (HPLC) has been developed for simultaneous preconcentration and determination of honokiol and magnolol in complex bio-samples. Several experimental factors affecting the extraction efficiency were optimized by single factor test.

Results: Under the optimized extraction conditions, the proposed method exhibited good linearity of not less than 0.9998, satisfactory precision with relative standard deviation of less than 1.3%, and acceptable mean recoveries of 97.3% and 101.5% for honokiol and magnolol, respectively. Furthermore, the method exhibits extremely high sensitivity with detection limits of 0.0097 and 0.0231 ng/mL, which is even more sensitive than those methods developed by MS.

Conclusions: The method established in this study is fast, economic, accurate, easy to operate, and importantly well suited to the extraction and analysis of honokiol and magnolol in a real complex sample matrix.