Agilent ICP-MS MassHunter PA Factors

There are several ways to approach PA (Pulse-Analog ratio) Factor determination. You can run the PA factor calibration during Startup using Agilent provided solutions or make your own custom PA solutions. To successfully calibrate a PA factor, element concentration must be high enough such that the detector can see the ion signal in both pulse mode and analog mode. These concentrations are therefore not trace level and there is a risk that running these high concentration solutions may actually elevate the background for some elements (contaminate the system).

It is therefore recommended to now determine PA factors inside the batch during calibration. MassHunter can automatically determine the PA factors using just the calibrations standards. This minimizes the elements that are analyzed on the system to only those in the calibration. It also limits the number of high concentration standards to those already used, minimizing possible sources of contamination.

Also, by determining PA factors in the batch, we have the added option of determining tune mode specific PA factors. Because kinetic energy differs for elements by tune mode, the resulting PA factors can be slightly different for elemental ions in different tune modes. When determining PA factors in a batch, select Independent PA Factors and MassHunter will determine a PA factor for each elemental ion per tune mode, providing a more accurate result.

Attached is a brief description of PA Factor determination from MassHunter software.

  • Hi,

    Is this PA 'within batch' option available in all versions of ICP-MS masshunter system control?  Or only from a specific version number?

    And, does this imply that the purchase of PA factor solution is not really required, and is just a convenience product?

    Can you explain how to configure this in a reasonably current version MH instrument control interface?



  • Hi Bob, PA in a batch is not available in all versions of MassHunter. As far as I can remember, it is available since the version C.01.01 and upwards. By using the PA in a batch, you do not require a special solution. MassHunter will initiate the PA calibration, as soon as ~ 400k counts are reached. This happens mostly in higher standards so that you calibrate the PA table for your current batch. If higher concentrations are not needed in your batch (ideally you will measure inside your calibration limits), PA values will not be changed. I have received very positive feedbacks from my customers concerning the PA calibration in batch. 

    All you need to do is to put a check mark in the acquisition method for "PA calibration in batch", MassHunter will do the rest. 

  • Hi emretoprak, 

    For the elements we analyse, out of 12 only Mg reaches the minimum counts for PA factor in the highest calibrations standards. Would you recommend to add the factor solution at the end of calibration to do PA factor for the other elements? 

    Also, doing PA factor on startup how do I select the PA factor solution to be used as in that moment it's using only tuning solution? 

  • Sorry one more question. 

    We have been doing PA factor in batch, but we have one template just for that and we do every 2 weeks or 3 weeks. Do you think it is affecting our linearity? Only Mg uses the analog mode, but we notice there is usually more ISTD drifting on the highest concentration standards. 

  • Hi, 

    i think ISTD drift on higher standards has nothing to do with the P/A factor, but with the higher amount of matrix. 
    The P/A factors itself, do not change until the EM voltages changes. 

    Best Regards


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