Example 14: RT/Average RT (in standards)

• Scope: Peak or group

• Type: Double

• Find a function for average in aggregate functions

• Find a function to return a list of Matching peaks (AllMatchingPeaksOrGroups).

• Choose the MatchOption. Since you want a ratio for all peaks, choose MatchOption.Closest. It’s better here to use the delta so that the ratio is not computed with a peak too far away.

• Define the list of peaks where you want to search the matching peaks (CurrentSequence.AllPeaks).

Formula

Peak_RetentionTime/Average("Peak_RetentionTime", AllMatchingPeaksAndGroups(MatchOption.ClosestRT, 0.1, CurrentSequence.AllInjectionsOfType(SampleType.Calibration))) (evaluates all signals)

or

Peak_RetentionTime/Average("Peak_RetentionTime", AllMatchingPeaksAndGroups(MatchOption.ClosestRTOnSignal, 0.1, CurrentSequence.AllInjectionsOfType(SampleType.Calibration))) (evaluates only the same signal as for the current peak)