Quantitation of impurities

Hi all,

I want to quantify impurities in my sample. There are some known impurities that have been listed in the processing method. Additionally there are some unknown impurities that are not listed in the processing method as they only appered after 9 months during stability testing. In our plant, the user type "Analyst" (who perfoms the analysis) only has privileges for modify integration parameters and retention times. Is there any possibility to calculate the amount of the unknown impurities without defining them in the process method?

Thanks in advance!

Best Answer

  • Accepted Answer
    Ok so i presume you are using "Amount" as the calculation for impurities- ie response of sample/response of std * factor (if used). Whatever method you are using for calculating impurities, set your active peak in your processing method as Default (tick the Default Pk) and this will then calculate amounts/impurities for the unknowns. You don't need to populate CCalRef1 unless CCalRef1 is mentioned in the custom field used for calculation.


  • Is your impurity calculated as a percentage of your main active peak ie area of impurity/area of active area in sample? or is it done off the bracketing standards?

  • The amount of the impurity should be calcuated using the bracketing standards.
  • It *should* just be a matter of making sure you have a default peak and a ccalref assigned in the processing method and including unknown peaks in your report method. 
  • Thanks a lot! Now it works :D
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