Surrogates and Chemstation

[kverge]

I've run into a vexing problem with MSD Chemstation (ver D.02.00.275) and was hoping someone's figured it out in the past. I'm running a version of 524.2 (VOCs by P&T) that involves adding a known amount of a mixture of internal and surrogate standards prior to analysis. The calibration solutions all contain this IS/SS mixture at the same concentration.

The problem is that I need to report the %recovery of the surrogate compounds and not have them act as internal standards. I can't, for the life of me, figure out how to do this in Chemstation. If the compound type is set to anything other than I (for internal standard), the software seems to require a full calibration curve. If I set the compound type to 'S' for surrogate, for instance, it reports a value based on the regression curve - which is invalid, since they are present at the same concentration in all calibration solutions.

Hope that makes sense and that someone can help.

Thanks.

[kverge]

I figured it out, mildly embarrassing. Simply change the calibration from regression to average of response factors and change the calibration table to reflect the true concentration of the surrogates and Bob's your uncle.