Chromatography Forum

Can we run a Waters C18 CSH column with a 100% aqueous mobile phase without having any problem?

If not, what should be the minimum methanol or acetonitrile % in the mobile phase?

Thanks in advance.

https://www.waters.com/webassets/cms/su ... 3397en.pdf

The chapter "Storage": "...If the mobile phase contains a buffer salt, flush AQUITY UHPLC CHS columns with 10 volumes of HPLC grade water..."

So you propably can run CHS column with 100% aqueous. But for the safety I would go with 5% organic.

Hello

https://www.waters.com/webassets/cms/support/docs/720003397en.pdf

The chapter "Storage": "...If the mobile phase contains a buffer salt, flush AQUITY UHPLC CHS columns with 10 volumes of HPLC grade water..."

So you propably can run CHS column with 100% aqueous. But for the safety I would go with 5% organic.

If you check this document carefully , on page 8 in additional information (point 4) there is clear information that 100% aqueous mobile phase should be avoided. If there is no information that column is designed for high aqueous mobile phase you can have stationary phase collapse. Phase collapse is best described as a dewetting phenomenon. It can occur with organic solvent concentrations of less than 5% in the aqueous mobile phase and retention can be reduced gradually.

So I'd recommend column for high aqueous mobile phases.

Regards

Tomasz Kubowicz