An efficient, sensitive and accurate method for the detection of astragaloside IV in Chinese functional spirit by ultra-performance liquid chromatography–quadrupole-orbitrap mass spectrometry

Mainly consisting of Chinese white spirit and traditional Chinese medicine, Chinese functional spirit is a popular health food in China due to its healthy effects, such as resisting fatigue and enhancing immunity. As one of the major active constituents of Radix Astragali, astragaloside-IV (AGS-IV) commonly exists in Chinese functional spirit. However, the concentration of AGS-IV in this health food is still rarely known. We firstly report an efficient, sensitive and accurate analytical method based on ultra-performance liquid chromatography (UPLC) coupled with quadrupole-orbitrap mass spectrometry (Q Exactive MS) to determine AGS-IV in Chinese functional spirit. Conditions of UPLC and Q Exactive MS were optimized. Sample pre-treatment was done by diluting ten times to weaken the matrix effect. The limit of quantitation and the limit of detection were 0.5 and 0.25 ng mL−1, respectively. The recovery was 92.5–96.7% and the relative standard deviation was 0.8–1.6%. The regression coefficient was 0.9999. In both the selected brands, AGS-IV was at trace levels (76.7 and 59.8 ng mL−1, respectively), which is nearly thousands of times lower than in traditional Chinese medicine extracts. From this analysis method, AGS-IV in Chinese functional spirit for daily health improvement could be clearly determined, and meanwhile it could promote a more scientific and reasonable quality control of Chinese functional spirit rather than detecting the content of total saponins to represent all the efficacy components in it.