I need to purify a synthesized polymer from its catalysts. The mixture (polymer with Mw 14k and catalysts with Mw 700) is soluble in Methanol. However, the catalysts are not soluble in water while the polymer is dispersed in it.

My enquires are;

1- Is Sephadex G-25 is the right choice for this separation? and suitable for this polymer Mw?

2- Can I use Methanol only as a mobile phase or I should prepare Methanol/Buffer 25/75 v/v?

3- Can I use NaCl as a buffer?

4- Is narrow or broad column recommended for this separation?

Best Regards