通过沸腾盐酸水解产品，并通过冷却凝固不溶性产品。通过过滤、干燥和溶剂萃取分离所需物质。该方法适用于小于1.5%（m/m）的含量。

Hydrolysis of the product by boiling hydrochloric acid, and coagulation of the insoluble products by cooling. Separation by filtration, drying and isolation the wanted matter by solvent extraction. The method applies to contents less than 1,5 % (m/m).