Comparing Two Spectra in Two Windows
NMR analysis often requires the comparison of two spectra.
There are different solutions for different circumstances.
One scenario involves comparing the same kind of experiment conducted on two different samples
or to the same sample at different times.
Another involves correlating two different experiments conducted on the same sample.
Here we explain how to arrange two windows to compare their contents.
Depending on the task, comparing spectra in separate synchronized windows may be preferable to displaying them as overlays.
This is a general and fast solution, but by no means the only solution provided by iNMR.
Shortcut
Just press the y key. In many situations this is all you need.
How to Synchronize Two Windows:
- Open and process the two spectra.
- Choose Window > Tile Vertically (or Tile Horizontally, or Do Not Tile, according to your preference).
-
From the same menu, either choose Synchronize,
if you have applied the same experiment to two different samples, or choose Smart Marks,
if you have applied two different experiments to the same sample. This is not a strict rule.
Synchronize is the best choice to compare two homonuclear correlation experiments,
for example a NOESY with the TOCSY of the same sample.
- Synchronize: the navigation commands performed in one window (zoom, cut, panning, etc.) are sent to the other window too. Marks and cross-hair positions are mirrored as well.
- Smart Marks: Only the marks are duplicated, and only when the observed nucleus is the same. In homonuclear 2-D spectra, a mark placed on one axis is automatically reproduced on the other axis.
- To halt the mechanisms above, choose the same command again.
If you need to tile and/or synchronize more than two windows, use the Tile & Synchronize command. It opens a dialog where you can also set the order in which the windows will be tiled, from left to right and from top to bottom. The dialog also allows you to exclude specific windows from synchronization: move them to the bottom of the list and specify the number of windows to tile.
An alternative to synchronization is the Global Cross-Hair, found under the Tools menu. It lets you track the same frequency position across multiple windows without synchronizing zoom and navigation.
With the Overlay Manager you can see both spectra in the same window and calculate their difference.
Related Topics
Printing Your Spectra Always in the Same Way
Tabulating the Integrals of a Series of Spectra