EXTRACTION OF MAJOR ALKALOIDS FROM POPPY STRAW WITH NEAR-CRITICAL MIXTURES OF CARBON-DIOXIDE AND POLAR MODIFIERS

Near-critical extraction of major alkaloids from poppy straw was performed successfully with a simple device consisting mainly of two chromatographic pumps and a pressure regulator. The optimum extractant, consisting of carbon dioxide, methanol and water, gave a quantitative extraction of thebaine, codeine and morphine in 20 min. The method was compared with a classical liquid-solid extraction procedure and carbon dioxide was shown to act as a transporting agent of the extraction solvent (methanol-water) into the vegetable matrix. © 1990.