A simple and sensitive thin layer chromatographic analytical method is proposed for the identification of xanthic bases of guarana Paullinia cupana HBK in urine samples. The samples were obtained from the consumers of the stimulant drink and submitted to extraction with chloroform in alkaline medium. After evaporation of the extracts residues were transferred to silicagel G (0,25 mm) thin-layer plates and developed with ethylacetatecyclohexane-methanol, ammonium hydroxide 50:40:0,1 for 14,5 cm in the same dimension. The spots were revealed with Dragendorff-iodate chromogen agent.
caffeine; guarana; urine; thin-layer chromatography; toxicology