Spectrum Fitter

The Spectrum Fitter is a module for analyzing spectral scan files collected from component serial dilutions. It applies multiple global nonlinear least-squares (NLS) fitting algorithms to model dilution-dependent extinction curves and determine the solute’s intrinsic extinction coefficient (intrinsic spectrum). Fitted results are exported as a .dat file for downstream analysis.

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Spectrum Fitter

Process:

1. Load Scanfiles: Click Add Wavelength Scanfile to navigate to a file manager and load the serial dilution spectrum scan .csv files. A Load CSV Files window will pop-up to select the Delimiter-separated value, edit the header and inspect data.

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Load CSV file

Click Accept and the data will be imported and displayed on the Absorbance and Extinction Profile plot. Repeat for each scanfile in the dilution.

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Loaded Spectrum Fitter

  1. Perform Global Fit:

Click Perform Global Fit to navigate to the fitting controls for the Global Non-Linear Least Square (NLS) algorithms. For typical users the default settings are sufficient and users can Fit without any modifications.

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NLS Fitting Controls

3. Global Fit Results: Select Residuals or Overlay to display the results in the adjacent Overlay/Residual plot.

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NLS Fitted Overlay

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NLS Fitted Residuals

The results of the fit can be saved in the main us_extinction window. Enter a name and save the basis spectrum.