Determination of Ecdysterone in Dietary Supplements and Spinach by Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry

Ecdysterone is a naturally occurring steroid hormone of the ecdysteroid class. This group is widely marketed to athletes in dietary supplements as a "natural anabolic agent", advertised to increase strength and muscle mass during resistance training, reduce fatigue and ease recovery. The aim of the study was to develop and validate a straightforward approach for identifying ecdysterone in dietary supplements by means of ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Furthermore, due to the fact that ecdysterone is one of the compounds naturally occurring in spinach, the fit-for-purpose method for extraction and identification of ecdysterone in spinach is proposed. The validity of the developed method was confirmed with the use of a reference standard and the limit of detection (LOD) for ecdysterone was established at 1 mg/g supplement. The presence of ecdysterone was confirmed in all tested supplements at estimated concentrations ranging between 5 mg/g and 383 mg/g.