IAM chromaotography

[Leda]

Hi all,

I'm a liquid chromatography researcher trying to set-up an IAM (immobilized artificial membrane) chromatography method in order to be able to determine CHI IAM values of the unknown pharmaceutical discovery compounds. The issue is that when using a new batch of IAM LC column, basic control compounds tend to have significantly lower retention times and lower CHI IAM values that the ones stated in the literature, while for the acidic ones the opposite was observed (but less pronounced). If I try to analyze the same compounds with an old column, I get better correlation with literature values. This was observed previously and stated in the literature (publication from 2020), but it seems to be more significant with the newer column batches.

Does anyone deal with these kind of measurements? Do you observe the same? How do you use the data that you get if they are not comparable to the old ones?

Any insight would be much appreciated!

KR, Leda

[Chromavore]

Sounds like a column conditioning issue, looking quickly at the Regis IAM column care guide for example it just says inject until stable retention times are achieved which is a bit vague,

If you inject the same sample on a new column multiple (10-20+) times does the retention time shift at all? Never used IAM but seen some quite extensive column conditioning procedures in my time and this would be my first guess.

Best of luck,
Chromavore