How to get my ISTD to calculate

Hi all,

We are currently using a GC/MS with Masshunter version B.09.00 to run Semi-volatiles. We have noticed the ISTD is not calculating on any sample in the run. We get a response, area, and retention time for each ISTD, but under the "calc" column for the ISTDs no values appear. At the same rate, when exporting data from the instrument the ISTD is not included in the export file. We are able to export the surrogates and samples, but the ISTD is not part of the file.

I am sure it is some setting we have missed, does anyone have any ideas on how to troubleshoot? Any ideas appreciated!

  • Hello  ,

    If I'm understanding your question, the reason the ISTD does not have a calculated concentration is because the assigned concentration is used as the known portion of the relative concentration when calculating a target's concentration. If you want to monitor the stability of your ISTD response there are two outliers available, ISTD Response and ISTD Response Percent Deviation. Both of these require a high and low value to calculate, even if you only want to monitor one or the other. The percent deviation outlier is set as a deviation from 0% of the average response, so the lower limit would generally be set to a negative value. This is not necessarily clear from the description. 

    Not all of the shipping report templates display information for the ISTD. The Gen_Samples_ISTD Report Builder template does list the ISTD for each target along with the response. If you would like the ISTDs listed in the table with the other compounds you will need to edit the bindings, as ISTDs are excluded by default. You can follow the general instructions in this post to edit the desired template list or table and remove the filter that excludes ISTDs from being included.

    (4) MS Quant Report Builder customize template to add ISTD graphics from SIM data - Forum - Mass Spectrometry Software - Agilent Community

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