Abstract:

Objective: To establish a method for determining phytosterol content in Pterocypsela laciniata (Houtt.) Shih by
ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods: The contents of β-sitosterol
and stigmasterol at different harvest times and different parts of Pterocypsela laciniata (Houtt.) Shih were determined.
Samples were extracted with petroleum ether by reflux extraction, and β-sitosterol and stigmasterol in the extract were
separated by an Acquity BEH C18 UPLC column, with methanol and 1% acetonitrile as mobile phase. Atmospheric pressure
chemical ionization was applied for MS analysis in the positive ion mode, and quantification was performed under the
multiple reaction monitoring (MRM) mode. Results: Good linearity was observed for β-sitosterol and stigmasterol in the
concentration range of 0.2 to 25 μg/mL, with correlation coefficients of 0.9990 and 0.9997, respectively. The average
recovery rates were between 93.45% and 104.23%, with relative standard derivations less than 7%. Pterocypsela laciniata
(Houtt.) Shih was rich in phytosterol. Different positions of the plant harvested at different stages of growth were ranked in
decreasing order of the contents of β-sitosterol and stigmasterol as follows: basal leaves, leaves on the stem, roots at the early
stage of growth and roots at the later stage of growth. Conclusion: The method is sensitive, simple, convenient, accurate and
efficient, and it can be used for determining phytosterol.

Key words: ultra-performance liquid chromatography-tandem mass spectrometry, Pterocypsela laciniata (Houtt.) Shih, phytosterol