Empower Tip: The Debye Plot

In this tip, We learn about the Debye plot. The Debye Plot illustrates the angular dependence of the light scattering signal and fits the results to the basic light scattering equation (light scattering is proportional to concentration times molar mass). This tip continues from Empower tip of the week - Tip 457.

The equation for light scattering is illustrated in figure 1. The terms are as follows:

c = concentration (from either an RI or UV detector)

M = molar mass

dn/dc = refractive index term

P = angular term

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Click the Results tool in the upper toolbar and the Results window opens.

Click the Distribution tab which is next to the Peaks tab and pull the sash down to see the Distribution table.

Highlight the slice which is close to the apex of the peak, which in this case is at 15.029. Click the Debye Plot tab at the bottom of the window. Notice that the very first point on the far left is an outlier due to a noisy detector.

STEP 5:

We can exclude this point. Go back to the Method Set, right click on the Channel Set and select Properties. Deselect the channel which corresponds to this point which in this case is detector 2.

Apply the Method Set and look at the Debye Plot.

Final Note

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