Chromatography Forum

Hey!
I am looking for some advice on what columns we should have in our UPLC-MS.

We are running a Waters H-Class UPLC with

• Acquity UPLC Peptide BEH C18
• CSH C18

Our lab is primarily focused on peptide/PNA chemistry with some DNA work and some small molecule work. We only run gradients of water/acetonitrile + 0.1% TFA. We are looking to use formic acid on the other lines. We run time courses of reactions, purity checks of prep HPLC fractions, reaction monitoring, identification of products by MS.

If we wanted to invest in a new column or two what would add to our capabilities or improve what we currently have?

I would recommend adding a couple of mixed-mode columns for the analysis of small molecules. We have several of them. We also have something nobody has, which is mixed-mode core-shell columns. These columns combine high efficiency of core-shell with unique selectivity of mixed-mode. No ion-pairing reagent is ever needed since these columns have IP attached to the surface:

https://helixchrom.com/files/2018/07/Ap ... ep-100.pdf

https://helixchrom.com/files/2018/07/Ju ... Column.pdf

If you decide to add these columns to your portfolio I will guide you through method development.

Mixed mode or alternative phase chemistry would be my choice as well. The Waters T3 column is decent, not great for highly polars but much better than a fully endcapped C18. It may be quite similar to your CSH C18. I've used it on metabolite extracts and been pleased over a standard C18. They actually have a very nice column chemistry selection tool on their site, and it's not only their columns on it, makes it more useful. RP-amide or a PFP could be interesting as well. Really depends what you're aiming to separate. Or go HILIC if dealing with mostly polar small molecules.