Calculations for updated retention times

To correct the expected retention times, the application reads the current retention time and calculates the shift to the expected retention time. This shift, multiplied by a compound-specific weighting factor, is added to the expected retention time.

Shift = ActualRT - ExpRT

where
Shift	Time shift of the compound
ActualRT	Actual retention time of the compound
ExpRT	Expected retention time of the compound

where
NewExpRT	Corrected expected retention time of the compound
ExpRT	Expected retention time of the compound
Shift	Time shift of the compound
RTUpdate	Weighting factor (RT update factor (%)) of the compound

Updated Retention Times with Time Reference Compounds

You can use RT updates with or without time references. The shift and the corrected retention times of the time reference compounds themselves are calculated the same way as for any compound, using the RT Update function:

where
NewExpRT_Ref	Corrected expected retention time of the reference compound
ExpR T_Ref	Expected retention time of the reference compound
Shift _Ref	Time shift of the reference compound
RTUpdate_Ref	Weighting factor (RT update factor [%)) of the reference compound

The corrected retention time of a compound associated with a time reference is calculated using an additional factor:

where
NewExpRT	Corrected expected retention time of the compound
ExpR T	Expected retention time of the compound
Shift _Ref	Time shift of the reference compound
RTUpdate	Weighting factor (RT update factor [%)) of the compound
Factor	Factor for compounds with associated time reference compound (Factor)

In case of timed groups, the expected retention time, range start time, or range end time are only updated if you use time references or relative retention times.