**9.6 Purification of natural active copolymers**

Conventional purification methods are not specific and must be repeated or combined for highly purification. Although, (immuno) affinity-based procedures are rapid and specific; but they are expensive, and reagents from biological origin are needed. Also the interactions involved between the product and the support are often strong and imply the use of rather denaturing reagents (either for the product or the support) to attain an efficient desorption yield (Lemay 2002). SCE has introduced as a more suitable method for purification of natural products. This technique helps to remove trace impurities in the synthetic active biocopolymers from maleic anhydride and pinene (Jarzebski and Malinowski 1995).
