troubleshooting agilent 7000 gc/ms autotune peak fronting

[Christian_bios]

Hi,

My autotune in the gc/ms would not run anymore since the tune peaks show a broad shape with fronting.

However the problem can be solved by turning off the gas (N2, He) for Q2 (collision gas).

Anyone got an idea what could cause this problem?

Would really appreciate it.
Greetings
Christian.

[Rndirk]

Can you show a picture of the 69 peak of the tuning compound?

Could there be a problem with the gas supply of the collision gas (leak, empty tank,..)?

Can you still run something in MS/MS mode?

[Christian_bios]

Thanks for the fast response.

Here is a picture from the calibration peaks.

Yes, we can still run it in ms/ms mode. The signal in the 3. Quadruple is fine, even with collision gas.
However we can not run the autotune with collision gas: "on" since it messes up the signal in the 1. Quadruple.

We checked for a gas leak or low pressure already, we can confirm that there is no gas leak and the pressure is fine.

Here an image of the calibration peaks:

[Rndirk]

Thanks for the fast response.

Here is a picture from the calibration peaks.

Yes, we can still run it in ms/ms mode. The signal in the 3. Quadruple is fine, even with collision gas.
However we can not run the autotune with collision gas: "on" since it messes up the signal in the 1. Quadruple.

We checked for a gas leak or low pressure already, we can confirm that there is no gas leak and the pressure is fine.

Here an image of the calibration peaks:

I haven't encountered that yet. So to summarize:

No collision gas

- Q1 scan normal
- Q3 scan normal

With collision gas

- Q1 scan not OK
- Q3 scan normal

But you can still measure samples like before right?

[Christian_bios]

Yes, exactly.

[Rndirk]

I'm sorry but i can't help you further, i think it's best to contact Agilent.