Method for removing proteins during production of heparin

The invention provides a method for removing proteins during the production of a heparin. The method comprises the following steps: preparing a clarifying agent, pretreating an enzyme based hydrolyzing liquor, removing proteins, and filtering with a plate and frame filter to obtain a clear liquor. The method provided by the invention has the advantages that (1) proteins and other macromolecular substances co-precipitate due to complexing can be removed effectively, more than 95% of the proteins and macromolecular substances can be removed in one step, and the effective components in the heparin can be reserved to the maximum extent; (2) ethanol can be replaced, the traditional ethanol based precipitation process can be simplified, the production cycle can be shortened greatly, and the production cost can be reduced; and (3) the proteins and the macromolecular substances can be removed conveniently and rapidly without adopting additional equipment, the clarifying agent can be added directly in the course of removing proteins by adopting the existing process and can not cause any damage to the molecular structure of the stock liquor, and the procedure is short.