Difference between Autotune and DFTPP tune? Agilent 5975c

[echae]

As the title says, what is the difference, if any?

[Steve Reimer]

If you load the tune file then run tune wizard it will step through the various tune targets. The difference will be in the targets for the optimization routine.

[echae]

I see. The DFTTP had a list of parameters that Autotune did not, "Tune Targets mass 69=100%". I'm really new to this but my best guess is that it's setting 69 at 100% relative concentration, relative to the other masses, and you can enter what concentration you expect the other masses to be(?). So it's not user programmable for Autotune?

[James_Ball]

Autotune tries to maximize the instrument for the masses across the board, while DFTPP tune tries to optimize the mass sensitivity so that it will pass the EPA tune criteria for DFTPP where there are limits on how the masses are to relate to each other.

DFTPP tune also usually enables the Variable Entrance Lens Offset instead of holding it constant for all masses.

An autotune is a good general way to start off when first running an instrument, as the DFTPP tune uses that as the starting point for its optimization and the automated Air and Water check uses the autotune settings as its default I believe.

If you are required to pass the DFTPP tune criteria, just remember that the automated tune does not always hit it exactly so be sure to play around in the manual tune window to learn how to tweak the mass ratios if needed. Best to only manually alter Repeller, Ion Focus, Entrance Lens, Entrance Lens Offset and the Entrance Lens Offset variable numbers if you are a beginner. Ramping these lenses helps you to see how altering their settings affects each mass versus each other. But unless you really go crazy with the Emission Current and possibly blow a filament you can not really harm the instrument(just keep it in the 15-37 range and you should be ok). You can always rerun the Autotune and bring things back to a good starting point.

[echae]

Autotune tries to maximize the instrument for the masses across the board, while DFTPP tune tries to optimize the mass sensitivity so that it will pass the EPA tune criteria for DFTPP where there are limits on how the masses are to relate to each other.

DFTPP tune also usually enables the Variable Entrance Lens Offset instead of holding it constant for all masses.

An autotune is a good general way to start off when first running an instrument, as the DFTPP tune uses that as the starting point for its optimization and the automated Air and Water check uses the autotune settings as its default I believe.

If you are required to pass the DFTPP tune criteria, just remember that the automated tune does not always hit it exactly so be sure to play around in the manual tune window to learn how to tweak the mass ratios if needed. Best to only manually alter Repeller, Ion Focus, Entrance Lens, Entrance Lens Offset and the Entrance Lens Offset variable numbers if you are a beginner. Ramping these lenses helps you to see how altering their settings affects each mass versus each other. But unless you really go crazy with the Emission Current and possibly blow a filament you can not really harm the instrument(just keep it in the 15-37 range and you should be ok). You can always rerun the Autotune and bring things back to a good starting point.

Some really valuable info here, thanks!