Peak assignment algorithm in ChemStation

I am calibrating 40 peaks and while they are all baseline-resolved at mid-concentration, at higher concentrations peaks start shifting and an incorrect assasignment can occur.  Similarly, unidentified peaks close by can trigger an incorrect assignment as well.  Additionally, simply reprocessing with the same parameters can result in different assignment.  It seems that the algorithm is trying to maximize the number of assigned peaks prioritizing the number of assigned peaks over their closeness to the expected retention times.  Is my assumption correct?  How to get around it, within the constrains of the chromatographic method as it is right now?  Is there a comprehensive explanation of how this algorithm works so I can educate myself?  Thanks!

  • Hi

    Are you working on DHA /SIMDIS?

  • No, terpenes in cannabis essential oil (steam distillate extract from hemp flower)

  • would you be able to share your software type and version?

  • Thanks, - I figured it out!  I am using ChemStation B.04.03

  •  glad to hear you were able to figure it out!  Would you be able to share any tips or tricks with other Community members?  

  • Well, I tightened the retention time window and I avoided using overloaded chromatograms.  I still don't understand the algorithm and would love to learn more about it.  The question of assignment came up recently and I couldn't explain why peak assignment occasionally flip-flops for nearby peaks, especially at low levels

  • The Understanding Your ChemStation manual may be of interest, you can check it out here:

  • is this manual also applicable for MSD Chemstation F.01.03.2357, which is what my laboratory has?

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