Hello Everyone,

I am currently doing some research regarding nitroterephtalic acid modified polyethylene-glycol stationary phases. These type of columns provide better peak shapes for underivatized fatty acids, but I don't exactly know why. I have a suspicion that it's because nitroterephtalic acid acts as a proton donor while PEG itself is a proton acceptor. As we increase the number of nitroterephtalic acid groups in our stationary phase the less likely it will create hydrogen bonds with our acid analyte.
These type of columns are also widely used for aromatic compund measurements. What makes these columns more suitable for analysis than the simple PEG columns? Does pi-pi stacking have anything to do with it?

Thank You for help in advance!