I’m currently modifying PVA with folic acid using a DCC/DMAP activation strategy in anhydrous DMSO. Here’s a brief outline of my procedure:

The issue is: after the first dialysis step, the previously clear solution turned turbid. I’m not sure whether this is due to pH-triggered precipitation, unreacted folic acid, or DCC byproducts like dicyclohexylurea.

Have you seen something like this before? I'd really appreciate any suggestions or advice on how to troubleshoot or avoid this issue.

Thank you!