Chromatography Forum

Hi

I am working with ion pair RP HPLC. The composition of mobile phase is 0.005 M sodium 1-heptanesulfonate dissolved in water and mixing with acetonitrile.

When I am doing the degassing step of mobile phase using a kitasato and vaccum pump, the results is a lot of foam formation inside of kitasato.

Can you give some recommendations to prevent foam formation?

Thank you

JP

sodium 1-heptanesulfonate is a surfactant. It's not surprising for you to see foam during degassing by vacuum. Try degassing by sonication.

hi javier,
of course heptanesulfonate causes foam ,as JI2002 says difenitely sonication will fix that problem

If you choose to go for sonication, do remember that sonication without a vacuum usually has little, if any effect on dissolved gases.

Degassing water and organic solvent first might be a solution.