Varian CP-3800 GC - Hasn't been used for 10 years

[lisa.stafford]

Hi Everyone,

I just started a PhD program and the principal investigator of my research group has asked me to revive an old Varian CP-3800 GC together with a Varian Saturn 2000 MS. I just dragged them out from underneath a bench in the lab and have taken off the first few layers of dust.

Does anyone have any advice as to the best place to start?

I appreciate your time!

Sincerely,

Lisa

[Peter Apps]

Hi Lisa

How to proceed depends on a whole list of things.

What is your background - have you run GC-MS before. Have you done maintenance and troubleshooting, repairs ?
Is there anyone in the group who knows how to run this hardware, or is otherwise an "expert" on GC-MS ?
Is there anyone who knows whether this hardware was working before it was mothballed ?
Does it have a computer and software to go with it ?
Do you have a budget for spares and repairs, service calls and training ?
What do you need to use it for when (if) it is up and running ?

Peter

[CE Instruments]

Hi, you might be best off contacting the independent service specialists in your country to find out how much they would charge to do it for you. They can also take you through basic steps to see if the system is complete and viable to revive. If you don't have all the bits you need it may be cheaper to buy a complete GC/MS second hand installed than battle an old dead system. If you are in the UK we can re-install and we could supply a refurbished GC/MS for £5k per year for three years with full warranty cover for that period. You can then opt to extend or just drop to a lower contract level.
Good luck

[lisa.stafford]

Hello Peter,

Thank you for your response. I have a master's degree in chemistry and was in charge of the GC/MS in my previous lab before coming to this new program. However, care of the instrument mostly included unclogging lines, changing columns, and grumbling at people who insisted on injecting aqueous samples.

The instrument was donated and was working prior to arriving in our lab.

I found a tower under a bench in the lab which may have the software on it--looking into that today.

I don't know what the budget is for this instrument--I get the feeling that my boss is expecting me to do most of the work.

What it is to be used for is a very good question! I'm embarrassed to write that I don't know--but will definitely find out.

I spoke with a technician at Agilent yesterday (they bought out Varian) and he gave me some first steps. Based on this advice, I removed the turbo pump from the mass spec yesterday, inverted it 180 degrees and left it on my desk. His concern is that with the turbo pump lying on its side for ten years, should I try to start the instrument that the pump would "die."

Next I am supposed to take everything apart, clean it and examine seals for signs of aging and/or wear. I've been taking a photo at every point in the dis assembly process.

Should I be using acetone, ethanol, ....? Can you wipe parts with Kim wipes or should I let them air dry?

Thank you for your time!

Sincerely,

Lisa

[Peter Apps]

Hi Lisa

You sound as if you have it pretty much under control, and well done for getting advice over the phone from a service technician !

I would go cautiously with the dismantling and cleaning. The only really heavy contamination would have come from oil in the forepump, if you see none of that at the base of the turbopump than it will not have got to anywhere else and you do not need to strip everything down. I would do a routine user service type clean on the source etc, and check those seals. If they look dodgy then new ones are worthwhile. Overall go with rule 1: don't fix what ain't broke.

Acetone is a stronger solvent than ethanol, but I would be concerned if I found visible deposits inside an MS that needed wiping off with solvent. You can use kimwipes, but a rinse off with solvent afterwards is good to get rid of any little fibers.

Good luck, keep us posted.

Peter

[lisa.stafford]

Hi Peter,

I have a potentially absurd question: Do GCs coupled to mass specs only have the mass spec as the detector? I'm guessing that there couldn't be a FID as that would destroy the effluents but could my GC/MS potentially have another detector? I ask because I can't find one! So I don't know if it was removed at some point or if it never had one to begin with...

Thank you for your time.

Sincerely,

Lisa

[Peter Apps]

Hi Lisa

Usually a GC with an MS does not have any other detectors.

Peter

[tima]

I have run this model for about 5 years. First thing if you take off the turbo pump, check that the bearings are OK. OUr instrument (Saturn 2000) was hard on turbo pumps and we replaced quite a few because we had a small but significant foreline pump leak before we realized this was causing the turbo pump bearings to fail.

When you remove the pump, hold it upright and twist it while observing the vanes of the pump. These should move easily with this motion. If not then try moving the vanes by touching them slightly. If you cannot get them to move then the bearings are gone. This could be why the instrument was moth balled. The replacement cost for this pump is about $7500. Check this first.

I would clean the trap (easy to do) and check to see if you have the CD that came with the instrument. There are very good instructions on how to do some of the maintenance items with the Saturn.

If you have experience cleaning an ion source (Agilent 5971, 2 or 3) then the ion trap is a cake walk. The pieces are large. Watch out for the ceramic rings...they are fragile and easily broken if dropped. There is a specialized alignment tool and the instructions should be on the CD on how to use it.

Check the filament (there are two wires on the same assembly) with a mulitmeter to check continuity.

Good luck with this. I found the Saturn wasn't a very robust MS...lots of space charge effects so watch out you don't inject too much (high ug levels). I really liked the software. Even better than ChemStation from Agilent.

Timothy

[lisa.stafford]

Hi Everyone,

I was making some headway on this instrument until I tried to start up the vacuum system. I found a roughing pump that works and hooked it up but it won't hold a vacuum. I then went through and isolated each section to see where the leak is. The problem seems to be somewhere between the turbo pump seal and the transfer line heater. I made sure all the seals are clean and tight but I still have a leak! When I first start up the roughing pump it sounds fine but after about five seconds the leak noise becomes detectable.

Does anyone have any thoughts?

I really appreciate your time!

Sincerely,

Lisa

[Peter Apps]

Hi Lisa

Have you plugged the end of the transfer line where the column will connect ?

Peter

[lisa.stafford]

Hi Peter,

Yes, I did.

Thanks,

Lisa

[cleh]

Do you have a good O-ring installed on the transfer line? They tend to wear out easily.

[Peter Apps]

Hi Lisa

Have you plugged the end of the transfer line where the column will connect ?

Peter

Sorry, I had to ask !

Probably the next step has to be to replace all the O-rings.

Peter

[lisa.stafford]

Hi Peter,

I'm glad you asked, thank you!

My boss is going to take a look at it this afternoon. I'm hoping there is something simple that I've missed.

Lisa

[lisa.stafford]

Hi Everyone,

My boss wants me to hook up carbon dioxide to the GC--apparently this is how it was set up when it was last in use. The previous GC that I maintained didn't have any cooling mechanism. I'm wondering if this is necessary. For what type of sample would you need to cool the oven below ambient temperature?

Thanks for your time!

Lisa