Morning glory is rich in natural pigment and has a good development prospect. The natural pigment directly extracted from morning glory contains a lot of impurities such as protein, sugar, organic acid and tannin, which seriously affects the application scope of pigment, so it is necessary to purify it.

Macroporous adsorption resin has the advantages of stable physical and chemical properties, insoluble in acid, alkali and organic solvents, good selectivity, free from the influence of inorganic salts, mild desorption, simple regeneration, long service cycle and so on.