Masshunter method setup for ISTD recovery

Question

Hey, I am new in the field and still learning both Chemstation and Masshunter. I was recently tasked to convert our Chemstation to Masshunter. I already have translated both data and methods using the translation tools but I have a problem to which I can&rsquo;t seem to find the solution. 
 I have multiple ISTD&rsquo;s that are added in the samples and thus follow the whole sample prep. After the sample prep, another ISTD called &ldquo;IS recovery&rdquo; is added to the samples. This IS recovery is added with the same amount and is used to calculate the recovery of the ISTD&rsquo;s after sample prep. With the translation of the Chemstation method to Masshunter, the IS recovery is now set as a Target and linked to ISTD 4 (probably because of the retention times being so close). As this IS recovery is added after sample prep it is not a "Surrogate" or "Matrix Spike" for as far as I understand. 
 How can I now change the method setup so that I can calculate the recoveries of the ISTD&rsquo;s based on this IS recovery?

howard_sanford · Answer

Hello Achim_Hongenaert , 
 I apologize for the delayed response. 
 There are a few outliers that can be used for recovery calculations. If this compound is added to all samples then I believe the best option will be to call it a Surrogate in quant, even though in your method it may not be referred to as this. You can then assign it an expected concentration and assign limits for its recovery in the Method Editor under Outlier Setup Tasks->Surrogate Percent Recovery. 
 Let us know if this works for your method/setup or if you still have questions on how to setup your method.