Hello Scientists,

I tested my ADC (antibody drug conjugate) using a strong anion exchange chromatography. I ran a couple of water blank injections prior to injecting my ADC sample. I see a ghost peak right after ADC elution and hump right before ADC elution and these two abnormalities are present in water blank injections as well. I used a NaCl gradient elution method ( 5 - 35 min, 0 - 600 mM NaCl, 30C, 1 mL-min).

I cleaned the column with 50% Acetonitrile- 300 mM Potassium chloride pH-2.1 buffer for 2 hrs at 0.8 mL-min. I have used 5% Isopropyl alcohol, added 20mM NaCl in solvent-A (25 mM Tris pH-8.6) to minimize the hump and the ghost peak and it did not help. Please find the attached file for the chromatograms.

Please let me know if anyone has experienced this and how they resolved the issue.

Thank you.