Does anyone have any suggestions why my Monochloroacetic Acid peak is severely tailing using EPA Method 552? I'm using a DB5.625 column in an Agilent 6890N GC. I get a better peak with a DB1701 column, but more interference than the DB5.625.

Thanks,
Becky

Sounds like possibly the derivatization is not complete. The tailing sounds like a polarity mismatch with the column, especially since the peak shape is better with a 1701 column. Are you having problems with standards, samples, or both?