Development of Un-targeted Screening Method for Detection of Synthetic PDE-5 Inhibitors and Analogues Adulterated in Health Supplements on LCMS-IT-TOF

Sildenafil and other synthetic phosphodiesterase type 5 enzyme (PDE-5) inhibitors are used for treatment of erectile dysfunction (ED) in men. Sildenafil, tadalafil, vardenafil, avanafil and udenafil are the approved PDE-5 drugs in different countries. However, adulteration of PDE-5 inhibitors and their analogues are found in dietary supplements and health products in recent years. The adulteration is illegal and dangerous for consumers because none of the analogues is approved officially for medical use. Analytical methods based on HPLC and LC/MS/MS are used for detection of targeted PDE-5 inhibitors, but it is challenging to detect unknown adulterants in actual samples. We present here a novel un-targeted screening method using LCMS-IT-TOF and a MetID program with database function. A multi-event method was used to acquire HR-TICs with enhanced sensitivity. An un-targeted screening approach was established using a concerned compound database of thirty-two PDE-5 inhibitors and their analogues and applied to five health supplements obtained from local market.