Perform multi-peak fitting and integration of cyclic data.

• Purpose
  This app can be used to perform peak analysis of forward and backward traces of cyclic voltammetry data. A region of interest (ROI) can be set for the traces, and peaks can be manually assigned and fitted after baseline is subtracted. The integrated area within the ROIs and the peak properties of the fitted curves can be reported to a worksheet.
• Installation
  Download the file "CyclicVoltammetry.opx", and then drag-and-drop onto the Origin workspace. An icon will appear in the Apps gallery window.
• Operation

         Note: If you have data files from Gamry Instruments, you can use the Import Gamry Voltammetry Files App to import your data.

1. Click the Cyclic Voltammetry icon in the Apps Gallery window to open the dialog.
2. Select columns representing scan index, voltage and current. The Peak Direction option is used to specify the direction of peaks in forward or backward trace. By default, the forward trace contains positive peak, and the backward trace contains negative peak. If your data is reversed, set this option correctly.
3. Click OK.  A graph named Cyclic Voltammetry Tool and a workbook named Cyclic Voltammetry Calculations will be generated.
4. Click left or right arrow at the top of the graph to change scan index.
5. In the bottom panel of the graph, move/resize the rectangles to define the region of interest (ROI) for the forward and backward traces.
6. The two middle panels show data within ROIs with a an asymmetric least square (ALS) baseline(ALS) .
7. The two upper panels show data within each ROI, after baseline has been subtracted.
8. Click Set Peaks button and then double-click inside the upper panels to set desired number of peaks and the approximate peak locations.  
   Up to 10 peaks can be assigned per trace. To assign fewer than 10, simply select desired number of peak locations and then press Esc key.
   Lines representing peaks chose will be displayed.
   To change or re-assign the peak locations, simply click the Set Peaks button again, to start over.
9. Click the Fit button to perform multi-peak fitting of the data using the specified initial peak locations
10. Once satisfied with the fit, press the Report to Sheet button. The integrated area calculated from the shaded area in the middle panels, and the peak fit parameters will be added to a  report workbook in two separate sheets named Integrated Area and Peak Details. (Notes: The area column in the Integrated Area sheet denotes the area of the peak under ROI, and area column in the Peak Details sheet denotes the area of each fitted peak.)
11. After manually analyzing all scans, click Close to close graph page and delete all intermediate sheets except the report sheet.
     

• Sample Files

             The App contains an Origin project file with sample data. Right-click on the App icon and select Show Samples Folder to access the file.

v1.33:6/7/2024 Improve fitting for negative peak in forward trace.
v1.31:5/31/2024 Fix pickpts issue in 2024b.
v1.3: 02/17/2023 Better specify cyclic direction.
v1.11: Fix peak report bugs.
v1.1: Fix bugs with comma separator data.