In the Processing Method window, select the SystemSuitability > Properties node.
Under Peak detection performance, set Signal to noise to All Peaks.
The EP, USP, and JP check boxes are only relevant for the column performance calculation, not for the peak detection performance. |
Select the required Noise calculation and Noise range settings. Choose the settings according to the current pharmacopeia guidance and according to the Standard Operating Procedures in your laboratory.
Noise calculation - see Signal-to-noise calculation
ASTM - see Noise Calculation by the ASTM Method
6SD - see Noise Calculation Using Six Times the Standard Deviation
P2P - see Noise Calculation Using the Peak-to-Peak Formula
RMS - see Noise calculation using the Root Mean Square (RMS)
Noise range - see Signal-to-noise calculation
Noise range based on the peak width:
Noise range Automatic: the noise is calculated in the last blank run (sample type = Blank) which was acquired before the injection. The range is calculated at the retention time of the peak -10 and +10 times the half peak width on the corresponding signal.
Noise range Relative: the noise is calculated as n times the peak width at half height. The range is calculated in the last blank signal.
Noise range based on a time range:
Noise range Fixed from: the noise is calculated in a fixed range of the current signal or the last blank signal.
Noise range Relative from: the noise is calculated in a given time range before peak start or after peak end. The range is calculated in the current signal or the last blank signal.
Reprocess the injection.
In the Injection Results window, display the S/N and Noise columns.
The S/N column contains the signal-to-noise ratio as calculated with the chosen algorithm. The S/N EP and S/N USP columns will be empty after reprocessing. |
For details on the calculation, see System Suitability Calculations.