Adsorption of caffeine, hydrochlorothiazide, saccharin, sucralose, and sulfamethoxazole from aqueous matrices (water and effluent of a wastewater treatment plant) onto activated carbon. Two activated carbons were characterized using different techniques and adsorption was studied varying the pH of the media. The quantitation of the compounds were carried out using bidimensional chromatography coupled to tandem mass spectrometry (LC-UHPLC-MS/MS).