Solid-liquid extraction was performed in a batch extractor, from aerial parts of Fumaria officinalis, in order to obtain an extract containing protopine. This study relates the influences of the temperature and nature of the solvent on the kinetics and rates of extraction. A method to quantify the protopine contents by Reverse Phase-High Pressure Liquid Chromatography was initially perfected. Then, a batch-extraction model based on the assumption of a second-order mechanism was developed to predict the rate constant of extraction, the saturated extraction capacity and the initial extraction rate with various temperatures in two solvents, water and ethanol 44% (w/w) in water. Furthermore, the activation energies were determined as based on the second-order rate constants of extraction used for the model building. The values resulting from these calculations and experiments were compared and discussed. (c) 2006 Elsevier B.V. All rights reserved.