Objective: To explore the major compound in Polygonati Rhizoma (Huang Jing, 黄精) for quality control. Methods: The major compound was isolated and analyzed by liquid chromatography-mass spectrometry (LC-MS), and subsequently further identified by nuclear magnetic resonance (NMR). Thin layer chromatography (TLC) was optimized based on the previous methods reported in the Chinese Pharmacopeia (2015 edition). Results: The major compound was isolated from the natural material and identified as linoleic acid. A high performance liquid chromatograph...