Extracting spectral regions (XL and XT)
There are two different tools available in NUTS for extracting part of a spectrum.
Extract Line (XL) — This command extracts just the displayed Zoom region, places the biggest peak in that region at the center of the extracted spectrum, and adds zeros to both ends of the spectrum so that the final size of the extracted spectrum is the same as the original spectrum. This was initially created for use with reference deconvolution.
Extract region (XT) — This command extracts just the displayed Zoom region. The resulting spectrum has a data size equal to the number of points in the zoom region. This can be useful for overlaying spectra that were acquired with different offsets.
Begin with a spectrum of ethyl benzene.
Use Zoom to expand so that just one peak is shown, in this case the water peak.
Exit zoom with <Enter>.
After executing XL, the spectrum consists of just the water peak, shifted to be in the center of the spectrum (zero frequency), and zeros are added to both ends so that the final data size is the same as the initial spectrum.
This is a kinetics experiment run on a spectrometer without a field/frequency lock, so the field moved during the course of the experiment.
The task was to create a display with the peaks correctly lined up.
Expand each spectrum to the same frequency limits, being sure that each spectrum is correctly referenced.
Execute a XT operation on each spectrum, saving the resulting files.
The extracted spectra were converted to a 2D file and now the peaks line up.
(To create a 2D file from a series of 1D spectra, run this Link:
- GA SC IN
and supply the name of the 1D files and an name for the 2D file to be created.)
See also: X0 – X9 to extract pre-set spectral regions.
Last updated: 5/18/98.