Simultaneous determination of yohimbine,sildenafil, vardenafil and tadalafil in dietary supplements using high‐performance liquid chromatography‐tandem mass spectrometry

A simple and sensitive method was developed for determination of illegal adulterants (yohimbine, sildenafil, vardenafil and tadalafil) in dietary supplements by HPLC‐MS/MS. The separation was achieved on a C₁₈ column with the mobile phase consisting of acetonitrile and 0.1% acetic acid aqueous solution with a gradient elution at a flow rate of 0.5 mL/min. The analytes were quantified and identified by two characteristic transitions using the multiple‐reaction monitoring mode. The recoveries of the analytes ranged from 77.5 to 109.3% with the RSD less than 8.1% (n=6). The method has been successfully applied to screen illegal adulterations of natural dietary supplements.