Determination of Withanolides and Withanosides in Ashwagandha Based Products Using HPLC-Drift-Tube-Ion-Mobility Quadrupole Time-of-Flight Mass Spectrometry.

A total of 19 products based on extracts from Withania somnifera (L.) Dunal, better known by its more common name ashwagandha, and five products based on ashwagandha root powder were analyzed with respect to their content in the biologically relevant substances belonging to the group of withanolides and withanosides. Using HPLC coupled to drift-tube ion-mobility quadrupole time-of-flight mass spectrometry (DT-IM-QTOF-MS), 19 withanolides and withanosides could be tentatively identified. The comparison of the results from the quantitative analysis with the information on the product labels showed that the percentage of withanolides and withanosides deviated from the stated specifications by at least a factor of two and at most a factor of 35.