If a signal contains poorly-resolved peaks, it is not easy to measure the intensities and positions of individual peaks even f the signal-to-noise ratio is very good.
This App improves the apparent resolution of the peaks using 2nd and 4th derivatives of the signal.
Download the file "Peak Resolution Enhancement.opx", and then drag-and-drop onto the Origin workspace. An icon will appear in the Apps gallery window.
Highlight the column with the XY data range in worksheet, or start from a graph of the desired data. Click the app icon from the Apps gallery window to open dialog.
The dialog offers the following settings
- Smooth Settings
- Smooth Method: No Smooth, Adjacent-Averaging, and Savitzky-Golay.
This is used to decide whether to smooth the signal before enhancing the peaks.
Select a method and adjust the number of points etc as suitable for your data.
For more details about the smoothing methods, please refer to this page.
- 2nd Derivative Weighting Factor: Please refer to K2 in the Algorithm below.
- 4th Derivative Weighting Factor: Please refer to K4 in the Algorithm below.
The following expression is used for the peak resolution enhancement.
EnhancedSignal = Y - K2*Y'' + K4*Y''''
where Y is the original signal, Y'' and Y'''' are the 2nd and 4th derivative of Y respectively, K2 is the 2nd derivative weighting factor, and K4 is the 4th derivative weighting factor.
For more details on the algorithm, please refer to this page by Prof. Tom O'Haver, Department of Chemistry and Biochemistry, The University of Maryland at College Park.