Chromatography Forum

Hi

i hope everything is good with you guys.

First of all thank you so much in advance for reading this post and try to help me.

My problem is:

When i change my chromatographic column after check the air and water i performed a autotune from the file created when the technician come to do the qualification "a good one". That tune give me a error defined in the subject of this post "improper masses for mass axis calibration". I try to performe a tune from default setting and the same error occurred.

I clean the ion source prior to do this.

My MSD is a Agilent MSD 5975C.
Software OpenLab CDS 2.1

I don´t see in this forum or other foruns this particular error, and the agilent troubleshooting guide does not have anything about this.

I will clean again my ion source to see if this problem dissapear.

i ask if you guys see something like this in your years of experience.

Thank you so much

If you go into the tune window and use manual tune, what are the masses listed under the tune parameters menu? They should be 69,219,502 for doing a mass width calibration, and it will work for mass axis also. The only major masses in the PFTBA tune gas are 50,69,100,131,219,264,414 and 502. There are others but they are of very low abundance.

If somehow the tune file has the wrong masses then it can not find them to do the mass alignments.

Hi James,

Thanks for the answer.

We already check the masses and we are using:

- m/z 69
- m/z 219 for the repeller optimization
- m/z 502 for ion focus optimization

We clean the ion source again but the same error occurs with differents tune files.

When we perform a tune from default and the entrance lens (V) parameter some times goes to 0.0 at the time of the tune.

Thank you so much for the answer.

Best regards

Did this error appear after a source cleaning?
As in did two wires get reversed? (blue in the back)
Can you scan in manual tune and see the 3 peaks listed?
I find Agilent error messages often to be less than helpful in pinpointing the problem.

Hi James,

Thanks for the answer.

We already check the masses and we are using:

- m/z 69
- m/z 219 for the repeller optimization
- m/z 502 for ion focus optimization

We clean the ion source again but the same error occurs with differents tune files.

When we perform a tune from default and the entrance lens (V) parameter some times goes to 0.0 at the time of the tune.

Thank you so much for the answer.

Best regards

Almost all of my tunes run entrance lens at 0V, and I run entrance lens offset as variable. I find if you need volts on the entrance lens it is usually dirty.

As mentioned below be sure the orange and blue wire are not reversed, I have done that several times. entrance lens is the one closest to the quads and it is labeled on the ceramic the wire comes out of.

Also look to see if the bare wires that are around the quads are not touching anything. I have bumped those before and moved them so they make contact with something, that is the RF and DC to the quads and if it gets shorted it can cause problems also.