Sugaring-Out Assisted Liquid/Liquid Extraction Coupled with HPLC for the Analysis of Honokiol and Magnolol in Traditional Chinese Herbal Formula Huoxiang-Zhengqi Oral Liquid

Abstract

Based on the phenomenon that the acetonitrile–water system can form phase separation in the presence of sugar, a sugaring-out assisted liquid/liquid extraction coupled with HPLC protocol was proposed for the determination of honokiol and magnolol in traditional Chinese herbal formula Huoxiang-Zhengqi oral liquid. Extraction conditions such as the type and concentration of sugaring-out agent, the volume of acetonitrile, pH value, temperature, and vortex time were investigated. Separation was performed on a Diamonsil C₁₈ column (150 × 4.6 mm i.d., 5 µM) with acetonitrile and 0.05% formic acid (60:40, v/v) as mobile phase. The column effluents were monitored at 254 nm. The method showed good linearity for honokiol and magnolol in the range of 0.5–50.0 µg · mL⁻¹, and the limits of detection were 13 and 24 ng · mL⁻¹, respectively. RSD values for repeatability and reproducibility were less than 1.62% and 1.80%, respectively. The recoveries were in the range of 85.8–103.7%. Compared with the Chinese Pharmacopoeia method, the established method was simple, fast, and greatly reduced the consumption of toxic organic solvent. Statistical test showed that the analytical results for the determination of the same sample by the two methods had no significant difference.

Keywords:

• acetonitrile
• high performance liquid chromatography
• honokiol
• Huoxiang-Zhengqi oral liquid
• magnolol
• sugaring-out assisted liquid/liquid extraction

The authors also thank the Human Resources and Social Security Department of Hebei Province for the financial support from the Scientific and Technological Foundation for Selected Overseas Chinese Scholars (2011). Special thanks are given to the project sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry of China.