Setting dwell time in GCMS

[Edde]

I'm setting up a GCMS method on Agilent instrument. I wonder if the dwell time needs to be set the same for all ions within a group and between different groups. The Agilent Chemstation manual recommends same dwell time be set but did not specify within a group or between a group. Is it a general practice to optimize dwell time for all ions by experiments?
Please kindly advise. Thanks.

[Don_Hilton]

Like my laywer says: It all depends.

If you are looking at ions with about the same abundances, the same dwell time for for each, across the board should be just fine. If you need a bit more sensitivity for a partiulcar ion, you can dwell longer on that ion. Just remember: what you give to one, you take away from the others.

[Edde]

Thank you very much. Do you mean I can set the dwell time as high as 100 msec for some ions as long as the number of cycles / peak comes out to be within 12-25 per peak as suggested by the Agilent manual? I guess I have to test several settings on the samples.