Masshunter Quantitation EPA8082 PCB Aroclor integrations with shared peaks

Masshunter Quantitation 12.1

We are using the Agilent-described method for Aroclor analysis with compound grouping and concentration sum math. I have also tried Response sum and average.

This works great if we are only analyzing Aroclors 1016 and 1260 which share no peaks. However, when looking at the full list (1221,1242,1254, etc.)  some of these have 3-4 peaks in common and therefore there will be a "hit" and associated concentration for the compound when not all 5 peaks are present in the sample. We overcame this in Chemstation by having separate methods for 1016/1260 and all of the rest of the congeners. And also we could QDelete the total compounds.

How can we change the method so that if any of the 5 peaks are missing then it will call the specific Aroclor as Non-detect? As it stands now, we still need to manually zero out many of the congeners because they had hits on 1-4 of the peaks but were not really in the sample. And you can't 'zero out' a compound math peak, so we have to go in and delete all of the detected peaks in each congener.

Thank you for your help,

Ryan

  • Hello  ,

    I'm not aware of any built-in way for quant to handle target qualification like this. It should be possible to use the SDK and quant scripting to accomplish this, but it would require Python or C# programming.

    The only thing I can suggest to assist with zeroing out the peaks manually is to utilize the Compounds at-a-Glance view, organize by compound group, and arrange the layout so that you can review and then perform multiple peak zeroing at once. Multiple compound chromatograms can be selected at a time and any manual integration operations will be performed on all of them at once. You could also enable the outlier Peak Not Found to assist with highlighting potential issues.

  • Thank you for your help  .

    I have spent all day modifying the lims python code to accomplish the task that I described in my earlier post. 

    I was not able to get the Masshunter SDK working because the oldest visual studio version now available for download is 2015, so I can't replicate the conditions that were used in all of the tutorials. When trying with visual studio 2022 and iron python 2.7 I was not able to get any of the solutions to compile and debugging would not start either. If you could provide any modern resources on this information, I would greatly appreciate it.

    Trying to modify the lims.py code manually and then running the report over and over is quite time consuming. In the end, I do have a working code that satisfies my requirements. I will present your compounds-at-a-glance option to the analysts and see if we can use this to solve our needs.

    Thanks again!

  • Hello  ,

    Product support is aware of the issue with Python debugging and VS 2022 and is working on a solution. Currently the only workaround is to utilize C# instead of Python, as the debugging for that does work.

    If you have full access to VS 2015 then that should work with Python debugging, or at least the free Community version that was available in 2019 worked. I was also successful with the free version of VS 2019 and Quant 12.1. As noted in my older post on using the SDK you must perform a custom install of VS and choose to add the Python Tools.

    If you are using Visual Studio 2015 you don’t need to download the Python tools separately. When installing VS 2015 choose to perform a custom install, expand the section for Programming Languages and choose Python Tools for Visual Studio.

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