So I am having issues with our Water 600 HPLC getting liquid (acetonitrile and water) into the sparge lines. We are running He through these lines for degassing purposes. Only one line has been affected while the other three are fine, though we are running similar solutions through them as well. We have tried to clean it out but are having difficulty getting rid of all the liquid.
Any suggestions on what might be causing the system to put liquid into the sparge line and how best to get rid of what is already in there would be appreciated.

Thanks