Analyte lost on PL-Sax anion exchange

[pipettemonkey]

I've tried working out an anion exchange method for a natural peptide hormone. I use phosphate buffer in the mobile phase in a gradient from 0 to 1M NaCL. No active ligand is in the flow through, and no active ligand elutes.

I have done this with 10% acetonitrile and 30% 1-propanol in the mobile phase. Nothing has worked.

What's going on here?

[goxy43]

pH? phosphate concentartion? any organi added to the mobile phase, column temperature, detection? Separation system dimensions? Please specify a bit more closely.