Almost no abundance Agilent 5975 MS

Discussions about GC-MS, LC-MS, LC-FTIR, and other "coupled" analytical techniques.

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We have an Agilent 6890 Plus attached to an Agilent 5975 MS. It had been functioning perfectly, and we took it offline. Put it in storage for a few months.

I set it all up the other day and pumped down. The next day we went to look at the MS and we have almost no abundance at all. When we try to tune, the EMV would get set really high, and almost no signal. I aborted because I didn't want to see the EM get fried.

I vented the system and put in another EM. Same thing.Here's a picture: Image

EMV way up high. Almost no abundance. Before I put it in storage it tuned perfectly at 1300 EMV.

Any ideas what happened to make the signal just about totally disappear would be greatly appreciated.
You're not out of cal gas by chance, are you? Even if you do have some in the vial, are you sure the valve is opening?
I thought we may have been out of cal gas. We injected a standard and got no peaks. We looked at the run (2000 EMV for the run).

Abundances were about 200.

We are not getting any response.
Out of curiosity, what do your pressures look like with the gas valve open vs. closed?

With a .5mL/min flow of He, I get ~2.5x10^-5 torr with the cal gas valve closed, and about 7.5x10^-5 torr with it open. This is with a diffusion pump. These pressures won't necessarily translate to a higher flow rate, but you should definitely see a pressure increase with the valve open.
Do you have any signals at all in the MS, like for instance nitrogen at 28?

If the system has 2 filaments installed, try to switch between them just in case.
Reponses to questions:

Ben Hucherson: I shut the instrument down so I can disassemble and inspect the source. From what I can remember from memory, the vacuum was somewhere in the 10 to the -5 range. When I pump down again, I'll post actual values. Most likely Mon AM. The flow is 1 ml/min.

Rndirk: we see noise much like in the picture across the entire scan range. No giant masses at all. Nothing to indicate a leak. I would happy to see indication of a leak, however, there is no indication. If there was a leak, I would see a big response down low. Unfortunately there are no big responses anywhere in the scan range.

Most perplexing. We see very small abundances for cal gas at high voltage. No indication of a leak.
You may have a corrupt tune file. You may want to load the default tune file and try to tune again.
I just had a 5975 give similar problems. Turns out for ours it was the HED fitting. The spark plug looking wire that attaches to the side plate has a hole and the socket is supposed to have a tiny pin in the center, well the pin was broken and stuck in the wire instead. Lucky for us that pass through is replaceable, simple fix and everything works now. Without the HED getting volts, you won't get much signal at all.
The past is there to guide us into the future, not to dwell in.
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