GC-MS Carrier Gas Ran Out!

[chokichi]

Not sure if the tank just emptied naturally or a leak sprung up somewhere, but there's no more Helium carrier gas. The column flows are turned off, but should I be worried about damage to the MS?

Also, I've never had to shut down the MS. What's a typical procedure? I don't think there's a built in macro. If I had to guess I'd say shut off the voltage to the MS and let it cool then vent the vacuum through Chemstation.

Any help is appreciated thanks!

[Rndirk]

Cooling and venting is the only thing you need to do to shut down the MS. Some software/instrument versions do have a sort of macro for this. What do you mean by shutting off the voltage? Just make sure you don't turn on the filament when there's air in the system.

Also cool down the transfer line, inlet and oven.

Damage to the system depends how long the system was exposed to how much oxygen and water, and at which temperatures. It's hard to say really. After fixing the problem with your carrier gas, pump it down and run a couple of standards/samples after reaching acceptable air/water levels. Compare the results with those obtained before the leak.

[rb6banjo]

What model is your system? When there's a problem (power outage, etc.) my 6890/5973 or newer systems go into nonselfdestuct mode. Generally, all you have to do is download the setpoints again and tune it. If you think you've been sucking in air for a while, you might just wait a few hours to purge it all out. I don't think you'll have too many problems. If all of your vacuum is still holding, you probably haven't been drawing in catastrophic amounts of air.
Definitely tune it before your proceed with any analysis. Make sure all is well in that regard.

[chokichi]

What do you mean by shutting off the voltage?

I turning off the filament/letting it cool I guess.

If you think you've been sucking in air for a while

I don't think there's been any air in the system because when the tank pressure got too low the column flow was stopped and the valves shut.

We should get more helium tomorrow, and I'll be sure to troubleshoot and check the tune after purging with helium for a while. Thanks!