A quantitative method for the analysis of xanthine alkaloids in Paullinia cupana (guarana) by capillary column gas chromatography

摘要

The aim of the present study was to develop a capillary gas chromatography method for the quantitative analysis of caffeine in Brazilian guarana as seed powder, dried crude ethanol extracts, and lyophilized water extracts with the addition of 7β-hydroxy-ethyltheophylline as the internal standard. The experimental protocol, the conditions, the analytical instrumentation, the recovery studies, as well as the analysis of seven different commercial batches of guarana, are presented and discussed.