Application of central composite designs in the supercritical fluid extraction of tropane alkaloids in plant extracts A. Brachet, L. Mateus, S. Cherkaoui, P. Christen, J.-Y. Gauvrit, P. Lantéri and J.-L. Veuthey Analusis, 27 9 (1999) 772-778 DOI: 10.1051/analusis:1999143