ICP-MS manual tuning

I could use some resources on manual tuning for ICP-MS systems.


I'm a relatively new user, and I'm disappointed at the seeming lack of useful information available through Masshunter Help, Agilent user manuals, or online. 

 

Specifically, I'm looking for resources pertaining to how lenses, plasma settings, and various other tune parameters  affect sensitivities/peak shapes.

 

What are the purpose of the various lenses?  How do they affect the ion beam and sensitivities?

The same question for gas flows and all of the other various tune parameters.

 

 

We currently use a 7900 system for drinking water applications (EPA).  The autotune alone is often not sufficient to meet tune criteria, making manual tweaking necessary.

 

Thank you.

Parents
  • Hi,

     

    manual tuning can be a tricky thing and I don't have a manual describing every step, but also because the goals might differ between users.

    For typical liquid samples it is not even necessary. The auto tune function of MassHunter is terrific and will give you results near the optimum in a very short time.

    If you want to tune manually, the general approach is easy: Allow yourself the custom tune in the software, aspire a solution with your favorite elements (usually tune solution with Li, Y, Tl; but can be different for special applications) and change the lens voltage to achieve maximum sensitivity. Sometimes depending on the lens, you will get higher sensitivities for lower mass elements and lower sensitivities for high mass elements or vice versa... choose and weight according to your needs.

    The auto tune will give you a balanced result for the whole mass range but this is also adjustable with a right click in the tune window -> Tune -> Parameters for Auto Tune.

    The Plasma Mode pre settings can be trusted. Use General Purpose for most samples below 0.2% total dissolved solids. If you want to tune these, keep an eye on the oxide ratio (156/140). This should stay below 1.5% in no gas mode.

     

    Manual tuning is usually only done with fancy sample introduction systems like Laser Ablation, LC, GC or semiconductor applications. If you have some of this, tell me so I can give you more specific advice. Otherwise it is to trust the auto tune generally, but you can play around if you want without risk to damage your instrument as long as you stay away from the "override hardware settings" button.

     

    Best regards

    Matthias

Reply
  • Hi,

     

    manual tuning can be a tricky thing and I don't have a manual describing every step, but also because the goals might differ between users.

    For typical liquid samples it is not even necessary. The auto tune function of MassHunter is terrific and will give you results near the optimum in a very short time.

    If you want to tune manually, the general approach is easy: Allow yourself the custom tune in the software, aspire a solution with your favorite elements (usually tune solution with Li, Y, Tl; but can be different for special applications) and change the lens voltage to achieve maximum sensitivity. Sometimes depending on the lens, you will get higher sensitivities for lower mass elements and lower sensitivities for high mass elements or vice versa... choose and weight according to your needs.

    The auto tune will give you a balanced result for the whole mass range but this is also adjustable with a right click in the tune window -> Tune -> Parameters for Auto Tune.

    The Plasma Mode pre settings can be trusted. Use General Purpose for most samples below 0.2% total dissolved solids. If you want to tune these, keep an eye on the oxide ratio (156/140). This should stay below 1.5% in no gas mode.

     

    Manual tuning is usually only done with fancy sample introduction systems like Laser Ablation, LC, GC or semiconductor applications. If you have some of this, tell me so I can give you more specific advice. Otherwise it is to trust the auto tune generally, but you can play around if you want without risk to damage your instrument as long as you stay away from the "override hardware settings" button.

     

    Best regards

    Matthias

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