Determining the Levels of Four Phenylethanoid Glycosides and Five Triterpene Acids in Liuwei Dihuang Capsule Using Solid Phase Extraction with HPLC-UV

Yong Zhang; Xian-Liang Zou; Yong-Li Wang; Lu Gao; Gui-Xin Chou

doi:10.1155/2019/7609438

Determining the Levels of Four Phenylethanoid Glycosides and Five Triterpene Acids in Liuwei Dihuang Capsule Using Solid Phase Extraction with HPLC-UV

J Anal Methods Chem. 2019 Nov 7:2019:7609438. doi: 10.1155/2019/7609438. eCollection 2019.

Authors

Yong Zhang^{1

2}, Xian-Liang Zou^{1

2}, Yong-Li Wang^{1

2}, Lu Gao³, Gui-Xin Chou^{1

2}

Affiliations

¹ Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
² Shanghai R&D Center for Standardization of Chinese Medicines, Shanghai, China.
³ Xiuzheng Pharmaceutical Group Co., Ltd., Tonghua 134001, China.

Abstract

In this study, we used quantitative high-performance liquid chromatography equipped with an ultraviolet detector (HPLC-UV) and solid phase extraction (SPE) to determine the levels of four phenylethanoid glycosides and five triterpene acids in Liuwei Dihuang capsules (LDCs). LDCs were methanol-extracted and purified using a 500 mg/6 mL silica-based C18 SPE cartridge. Two elutions were analyzed on a ChromCore C18 column under two HPLC conditions. To improve the pretreatment clean-up, an array of silica- and polymer-based SPE cartridges were compared. Both wash and elution steps were also optimized to achieve the highest removal of impurities. Under optimal chromatographic conditions, good linearity was achieved for all compounds (correlation coefficient of r ≥ 0.999), with a quantification limit ranging from 0.0076 to 0.418 μg/mL. The method had satisfactory efficiency and reproducibility with recovery rates ranging from 91.6 to 99.3% with a relative standard deviation below 1.5%. Taken together, this demonstrated SPE as a suitable extension of HPLC-UV for the determination of phenylethanoid glycosides and triterpene acids in complex LDCs.