Chromatography Forum

I met a very strange thing.
After 50 injections of Dextran Sulfate and digested protein to SEC column (PSS Suprema 100 and 30, 10u columns), the system pressure is increased to 2000 PSI when using 0.2 ml/min from 200 PSI. Is this mean that the pores of SEC columns get stuck? I didn't get the instruction from the vendor yet.
Is there any experience to share?

Thank you so much.

The pores are probably not blocked. The fluid transfer in and out of the pores is by diffusion. The macroscopic flow is between the particles, and that is where your blockage is. If you are lucky, the crud is caught on the entrance frit, and you can simply change it. If you are not lucky, it has infilitrated the packed bed. You might be able to backflush the column (check the vendor's advise on reverse flow) overnight at a very low flow rate. The worst case is that the top of the column is so fouled that it forms a piston that compresses the bed; this can ruin a column.

In future, filter your samples to prevent this problem. You could also get disposable precolumn filters from any of the usual suppliers of HPLC accessories.