Determination of lignans in Wuweizi by using magnetic bar microextraction and HPLC.

In this paper, a magnetic bar microextraction was developed to extract schisandrin A, schisantherin A, and deoxyschizandrin from Wuweizi. The analytes were determined by HPLC. A stainless-steel wire was inserted into the hollow of the hollow fiber to make the magnetic bar. The bar can be used to stir the extraction system and extract the analytes, and was isolated from the extract system by magnetic force. Several experimental parameters, including type and volume of extraction solvent, the number of magnetic bars, extraction temperature and time, stirring speed and NaCl concentration were investigated and optimized. The LODs for schisandrin A, schisantherin A, and deoxyschizandrin were 0.14, 0.06, and 0.10g/mL, respectively. The recoveries were in the range of 70.90-106.67% and the RSDs were < 8.84%. Compared with ultrasound-assisted and Soxhlet extraction, when the present method was applied, the extraction time was shorter, the sample amount was smaller, and the consumption of organic solvent was lower.