Black particles in mech pump oil LC/MS

[oldspecguy]

I am running an Agilent 1100 LC/MS with an Edwards single Turbopump (ceramic bearings, I think) and an Edwards 18 mechanical pump. Less than 2 months ago, the turbo pump was replaced due to a failure. The new one is an Edwards rebuilt one. Before the turbo was replaced, I also changed the mechanical pump oil. Now after less than 2 months having it running - basically less than a handful of samples run - it looks like I might be having some power supply problems preventing operation, but it might also be a function of insufficient vacuum. I just changed the mechanical pump oil today and its completely loaded with very very fine black particles - enough to make the fluid look virtually black when disturbed.

I have never seen anything like this on any Mass spec or vacuum system I have worked on. I did swipe the intake metal hose just above the entrance to the mechanical pump with a gloved finger and found some black particles there too;there didn't seem to be any oil associated with them, ie very dry, so I don't think it was "kicked up" by the mechanical pump. I'm almost dreading the idea that it might be coming form the MSD of the LC-MS.

Has anyone seen this before? Any suggestions?

Thanks.

Oldspecguy

[bhuvfe]

Oldspecguy,

Do you know if these particles are organic or inorganic? (via IR or EDS?)

Do you use ''exotic'' solvents on your LC-MS?

Best wishes,

bhuvfe

[oldspecguy]

Don't know if it is inorganic or organic BUT I do know that it is coming from the MSD. I found the same type of "soot" in the flexible metal hose just downstream of the analyzer/turbo area. It looks like it is from either the "new" rebuilt turbo or remnants of the old failed one.

Primarily using Hexane with varying amounts of DCM (primarily 2-50%) - nothing exotic here. I am beginning to think it was something not done properly with the rebuilt turbo.

Agilent will be coming in the next week or so.

Thanks