Abstract: Provided is a method for separating and purifying fucoidan, including: S1, subjecting a Undaria pinnatifida powder to extraction in hot water, filtering, and concentrating by rotary evaporation in sequence to obtain a concentrate; S2, adding an aqueous calcium chloride solution to the concentrate obtained in S1 in batches, where the aqueous calcium chloride solution is excessive; S3, adding chitosan-crosslinked graphene oxide/ferroferric oxide to a resulting material system obtained in S2 to obtain a mixed system, placing the mixed system at room temperature, and chelating excessive calcium ions obtained in S2 while adsorbing proteins by the chitosan-crosslinked graphene oxide/ferroferric oxide; S4, conducting filtration to filter out a solid, and obtaining a liquid, which is an aqueous fucoidan solution; and S5, adding ethanol to a resulting concentrate obtained in S4 to precipitate the fucoidan, and then filtering and drying the fucoidan to obtain purified fucoidan.

Abstract: Disclosed is a solid acid catalyst for preparing D-galactose and a preparation method thereof. The method includes: S1. synthesis of a skeleton carrier: S11. preparation of a sodium aluminate solution and an organic template solution; S12. mixing the sodium aluminate solution with the organic template solution, and thoroughly shaking a resulting mixture to obtain a mixed solution; S13. adding a zirconium source to the mixed solution obtained in S12, and thoroughly mixing; S14. subjecting a reaction system obtained in S13 to a hydrothermal reaction to obtain a mixed crystal ZrO2/Al2O3; and S15. rapidly heating the mixed crystal ZrO2/Al2O3 obtained in S14 until the organic template is completely ashed, and washing a resulting product with absolute ethanol to obtain a white solid ZrO2/Al2O3; and S2. soaking the skeleton carrier obtained in S1 in concentrated sulfuric acid such that sulfonyl is loaded on the skeleton carrier to obtain the target solid acid.