Frequency of autotune on GCMS..

[Pegry]

Hi everybody,

I have just a simple question to ask to the forum. Which is the normal frequency to make a new tune on the gcms? I mean, do you make an autotune of the instrument every day, week or do you have some instrumental parameters (like system check, change of FWMH value) that you monitor to decide when to make a new tune?

Sorry for the easy question, but I would like to hear some opinions on this matter..

Bye

Davide

[Schmitty]

I used to tune everyday that I ran samples. Now, I just tune once every couple weeks. Excessive tuning can lead to problems in the source and create background problems...I think.

[MIB_EO]

Once the MS is set-up correctly it shouldn't need to be re-tuned for months at a time.
If your resolution starts to become noticeably worse than previously, that maybe an inidcator that the time has come for a re-tune, but resolution will be effected by temperature, and it may be easier to control the lab temperature than to continually retune.

Sensitivity issues should NOT be cause for an autotune function, you may have to manually tweak a few source parameters for a given compound, but not the main MS voltages which are adjusted during autotune.

Don't forget to recalibrate every time you autotune.