Displaying and Using I-t Plots
Displaying Peak I-t Plots

1. Select a peak in the chromatogram.

2. Select Show I-t Plots on the View menu or click the following icon on the Method toolbar:

 If the associated 3D_Amp data is available, thumbnail I-t plots of the peak are displayed in the chromatogram. The I-t plots identified by the thumbnails are displayed in the I-t plot window.

Depending on the settings, up to five I-t plots from the same peak can be displayed in different colors. These include the I-t plot at the retention time of the peak, and up to four I-t plots extracted at specified peak heights along the leading and trailing edges of the peak (for example, at 10% and 50% peak heights).

• To set the peak heights from which I-t plots are extracted, select Decoration on the View or context menu and select the Peak I-t Plot tab.

A reference I-t plot can be overlaid on the peak I-t plot. The reference plot is an I-t plot of the peak with the same name as the displayed I-t plot. It is extracted from a recent standard, a fixed sample, or the peak table.

• To overlay a reference I-t plot, select Decoration on the View or context menu and select the Peak I-t Plot tab.

I-t plots can be (height) Normalized. Normalization allows objectively comparing two I-t plots of different concentrations. I-t plots that largely match can indicate good peak purity.

• To select the type of normalization applied to the I-t plots, select Decoration on the View or context menu and select the Frame & Axes tab. Normalization is off by default.

Also, refer to:

Displaying and Overlaying Time I-t Plots

 Displaying Difference, 1st Derivative, or 2nd Derivative I-t Plots