If you are still asking about fucoidan purification by FPLC, I'd like to inform you that we succeeded recently to use our immobilized perylene diimide derivative to purify fucoidan using a FPLC protocol.
In addition, you can use gradient NaCl to obtain different fucoidan fractions, as Ke-Wei Zhao suggested.
For any question, don't hesitate to ask me.
Zayed, A., Process Biochemistry (2017), http://dx.doi.org/10.1016/j.procbio.2017.10.012