Parameter Set
|
|
Pulse Sequence |
cpmg |
| Experiment Description |
-
- Carr-Purcell-Meiboom-Gill experiment to measure Proton T2 relaxation values by eliminating the effect of magnetic field inhomogeneity on signal decay using a train of 180° pulses.
|
Scans per Slice
(ns) |
Dummy Scans
(ds) |
Recycle
Delay
(d1) |
FID Size
(TD, F2) |
# Slices
(TD, F1) |
F2/F1
Spectral
Width
(sw,ppm) |
Spectral
Center
(o1p/o2p, ppm) |
| 8 x ns (8) |
16 |
10 |
16384 |
10* |
20/NA |
6.18/6.18 |
| Sample Setup |
-
- To reduce convection:
- Select a highly viscous solvent
- Use a smaller NMR tube.
|
| Experiment Setup |
-
- Acquire basic Proton experiment and determine a spectral width and center of the spectrum so that no signals are close to the edge.
- Spin the sample
- Use getprosol or prosol button to read in proper pulse and power parameters
- Create a variable counter list (vc list) to create different 180° pulses train lengths. Each value must be an even number. A good starting list is 2, 4, 8, 12, 16, 20, 30, 40, 50, 100. Want to make sure the signal intensity reaches a null point. Save the vc list file.
- Change the TD value of the F1 dimension to match the number of values in the VC list.
- Change the VCLIST parameter to the file name of the list created above.
|
| Processing Notes |
-
- Fourier transform with the command xf2. Only need to process the F2 dimension
- Manually phase F2 dimension
- Use commands abs2 for baseline correction
- Convert your VCLIST into a VDLIST using the command convvc. This is important for proper calculation of T2 values.
- Open the T1/T2 relaxation Guide through the menu Applications->Dynamics->T1/T2
- Press FID button and in the 1st popup select “FID”, 2nd popup enter a value of “1”. This will process all slices based on the first slice.
- Next Press Peaks/Ranges button and select “Manual Integration” and integrate regions of interest.
- Once regions are selected, export integrated regions to relaxation module by pressing the the save/export icon (see below).
- Next, press the Relaxation button and it will extract integral intensities or areas and plot for fitting.
- Pressing the Fitting button will popup a fitting parameter list. Select the appropriate T2 function (uxnmrt2) to use in the fit. Make sure that the List file name is set to vclist (it will get the correct values from the vdlist created above). Press OK.
- Press Start Calculation to start calculating the T1 relaxation.
- Report button will display the Relaxation report complete with the fitting equation, parameter values, and peak information.
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| Sample Spectrum |
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