**4.2.3 Enzymatic method**

Phospholipids can be hydrolyzed by such phospholipase as phospholipase A1, A2, C and D. When treating the ethanol-treated phospholipids (containing minor PC), phospholipase selectively catalyze hydrolization of PE and PC but not PI. More special, alkaline or acid phospholipase catalyzes hydrolization of PA and some salts produced by PE hydrolization but doesn't act on PI, PC or PE. PI products used in various fields can be obtained by this method and the purity can reach up to 99%. Lypase can be used to purify PI as well, and the purifies are 60%-70% (Deng et al., 2003).

Enzymatic method has wide application prospect as it is simpler, more convenient and environmental prospective compared with solvent method and column chromatography.
