Tune report for ICPMS 7900

"I am new to Agilent ICPMS. I have a 7900. I run groundwater and surface water samples and use H2 gas for Be, Al, Zn, and Se and He gas for all the other analytes. For my EPA tune report, I run both gas modes but H2 has high peak widths. Do I have to run both gases in the semi autotune?

I may have to adjust my peak widths to read less than .75 amu at 5% peak height, and I have not seen my peak widths lower than .76amu when the parameters were set at .9 amu. The 200.8 method revision 5.4 has three different statements relating to the tune. Does anyone have experience determining which one to follow. My previous lab I worked at did .9amu at 5% peak height for every method.

I appreciate any help, I'm the only metals analysis in my current lab, so this forum is a wonderful support."

  • Hello,

    Agilent check the peak widths at 10 % and the usual range is between 0.65-0.8.  The semi-autotune is for a partial tuning.  If you only want to tune one mode.  In your case you work with both gases I recommend performing full autotune to adjust for both gases.  When you set a limit into the tune check you don't tune for that limit.  It's a parameter to evaluate the quality of the tune. 

    Usually, we recommend using 1ppb tune solution 5185-5959 for the autotune.  Unless you use ISIS3 (where the dilution for tuning is 10ppb) the dilution is 1:10. Using another range of autotune solution will affect the peak width and prevent the correct performance evaluation of the instrument. 

    We usually check everything is NoGas. For gases we have sensitivity range to account for performance of the instrument.  The method 200.8 prevent the usage of gases for autotune and stipulate that the ICPMS peak width must do 1amu at 5%. EPA 6020 is a better reference if you want to use gases for tuning.  

    Hope this helps.

  • Unfortunately the Auto Tune will not be the solution.

    The Mass Axis is set during the Startup Tests (Resolution/Axis), which are run after the Plasma start.

    I would recommend, to run these Test every Day. 

    The Software then aims for a Peak Width of <0.8 at 10%. If this doesn't fit with your needs, you have to "override hardware settings" in custom tune, but i strongly do not recommend this, unless you know exactly what to do.

  • From section 2.2 of the 200.8 method:  

    In other words, the ICP-MS needs to have a resolution of <1 amu at 5% peak height.

    Again, the same thing is re-iterated under System Requirements:

     

    Then, in section 10.2.1 where it describe what is needed in proof of performance it states the following:

     The operative word here is “approximately”. Not less than. That’s all the method is saying.  As long as you can demonstrate < 1 AMU at 5% peak height, you are in compliance.

    Then when it comes to EPA Method 6020 it says something similar but the instrument must be capable of <0.9 AMU at 10% peak height.  Therefore, if we set the software limits for <0.9 AMU at 5% peak height, we’ve complied with both methods which is why most customers use this as the requirement when running EPA methods. 

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