In the Processing Method window, select the SystemSuitability > Properties node.
Under Peak detection performance, set Signal to noise to All Peaks.
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.
The EP, USP, and JP check boxes are only relevant for the column performance calculation. |
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 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 Fixed: the noise is calculated in a fixed range of 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.