Calculating RRT using a peak from a different injection?

HI my standard is run separately in a different injection from my samples, is it possible to calculate RRT from the peak of this injection against the peak of another injection without having to do it in excel.

Best Answer

  • If you have the run already processed then yes, add the label A on your standard injection through Alter Sample then save. Make sure the custom field is created in the project and then reprocess the sample set- custom fields only give results if they are in the project at the time of processing. Create the custom field in the project and then reprocess the run to get results. 
    Also, in the custom field, be aware of your Search Order option, its best to pick "Result Set Only" if you normally batch process sample sets to generate result sets. If you manually process individual results, then a search order of Outside First may be more suitable. 


  • A custom field should do this. Set the peak that you want the RRT calculated off in the 'CCalRef1' field of processing method and set something simple like A in the sample set for the label of the standard. Then create a peak, real, calculated custom field of the formula: Retention Time/A.%.(CCalRef1[Retention Time]) which will give you RRT of all peaks off the standard peak in the standard labelled as A. 

    If you are running this standard several times, label all as A and amend the formula to Retention Time/A.%..AVE(CCalRef1[Retention Time]) and set the function Summarize Custom Fields as the last line of sample set. 
  • lizfig6
    edited January 2019
    In alter sample I would label that injection as standard correct? 
    Then in label place an a? 
    Do I need to add quantitate at the end or anything? Or label the injections I want to calculated with that same label? 
    I see the custom field in my processing method but I’m not getting any numbers in that space 
  • lizfig6
    edited January 2019
    Thank you!! It worked!!