Detection of Sildenafil Analogues in Coffee Powder by Liquid Chromatography Tandem Mass Spectrometer (LC-MS/MS)

The active ingredient in Viagra is Sildenafil which is used for the treatment of impotency or erectile dysfunction. Sildenafil has become one of the most commonly prescribed pharmaceutical drugs to cure sexual deficiency. In recent years, the use of this drug had been widely expended towards consumption for negative activities. Local authorities and media have reported the abuse of this drug such as taken in drinks, beverages or sweets. That was adulterated. To avoid detection, this erectile dysfunction drug was modified chemically and therefore known as Sildenafil Analogues. These analogues have slight difference in chemical structure, but they have almost the same effect as the original drug. In this study, five (5) local brands of coffee powder suspected to be adulterated with Sildenafil were analyzed. All the coffee samples were extracted with methanol and identified using LC-MS/MS. Each sample was qualitatively analyzed followed by confirmation analysis using two Multiple Reaction Monitoring (MRM) transitions selection, parent and daughter ions for Sildenafil Analogues. The expected chemical structure for parent and daughter ions in this study was also proposed.