Chromatography Forum

We have a MetaChem Degassit (model 6414) which I've just discovered is starving the pump of mobile phase and causing a significant drop in flow rate (85% of 1 mL/min). The problem is definitely the degasser, as I've fed the mobile phase directly into the pump without the degasser and the flow rate became 1 mL/min. (Mobile phase is 50% MeOH in water)

I've put a new inlet filter in the mobile phase reservoir; both the degasser reservoir sit a good 40 cm above the pump, and I've even tried raising the reservoir a further 30 cm higher. Also tried different plumbing configurations on the degasser. Nothing improves the feed to the pump. I've taken the lid off the unit and can see nothing amiss.

Is there anything else I can try or do I just need to buy a new degasser?

MeOH/ Water 50/50 has high viscosity and maybe you have a leakage in the degasser unit. The Teflon tubing in the degasser unit can be changed. Another possibility can be that the tubing is blocked. Please remember that the volumn of such a degasser is quite large and it can happen that a rest of buffer, mainly phosphate buffer is still in the tubing and you try to get Acetonitril through the degasser you will get a precipitation problem. If so, please flush the degasser with 500ml hot Water. Hope that will help. For all cleaning procedures please disconnect the column and detector.
Good luck