NMR Training Materials
NMR Experiment Setup

Bio-NMR experiments are heteronuclear and multi-dimensional experiments. These experiments constitute the connection between the time evolution and the RF channel for each acquisition dimension. The heteronuclear capability is provided by multiple RF channels for multi-nuclei (1H, 13C, 15N, and 2H).

Experiment Setup Bruker Procedure
General procedure:
(1) Call the experiment parameter file and (2) optimize parameters based on pulse calibration.
Setup by rpar and getprosol;
(1) The rpar command sets up the experiment parameter and (2) the getprosol command calibates pulses based on the prosol table (stored in system). Users cannot modify the prosol table but correct it temporarily by getprosol 1H pw90 power.
Experiments supported by Bruker library are set up by these two step procedures but any other home-built experiments need to use an extra step supported by home-built setup au programs.
Finding the 1H center frequency and 1H pw90

From the best water suppression, the 1H carrier frequency is set at the water proton ppm.
(1) rpar ZGW to find o1p of a water peak (no getprosol).
(2) rpar ZGPR, getprosol, and update o1p.
(3) pulsecal for 1H pw90 calibration.
(4) getprosol 1H pw90 power where the power is PLdB1.
(5) gs to optimize the offset frequency for the best water suppression.
Updated o1p and calibrated pw90 should be used repeatedly for all other experiments.

zg; acquires spectra.
ft; FT
apk; automated phase correction
RF Channel Setup
Default channel setup for Bio-NMR
1H for channel 1,
13C for channel 2,
15N for channel 3,
2H for channel 4
RF Channels and center frequencies
F1 (NUC1 1H), O1 (O1P), SFO1
F2 (NUC2 13C), O2 (O2P), SFO2
F3 (NUC3 15N), O3 (O3P), SFO3
F4 (NUC4 2H), O4 (O4P), SFO4
edasp; to setup the channel configuration
No confusion with dimensional parameters because F1,F2, F3, ... are used for multi-dimensional acquisitions.
Main Pulse Parameters
Nucleus, PW, Power in dB (Power in W)
1H, P1, PLdB1 (PLW1)
13C, P3, PLdB2 (PLW2)
15N, P21, PLdB3 (PLW3)
Bruker uses 'cortab' to the amplifier linearity.
1D Acquisition (1H)
  • This is also the direct detection dimension in multi-dimensional NMR.
  • Since 1H is acquired, the 1H channel parameter is used for this dimension.
  • The acquisition time (aq in Bruker) is limited to 0.1 sec when decoupling is used during acquisition.
Dimensional parameters; TD, SWH (SW)
The acquisition mode is DQD as complex.
Other parameters; D1, AQ(=0.5TD/SWH), NS, DS, RG
2D Acquisition (F2, F1)
F2 is the direct detection dimension.
F1 is the indirect detection dimension.
  • In Bruker, the F1 quadrature mode is provide by FnMode parameter, so it specifies States-TPPI or Echo-Antiecho.
F2; SW (SWH), TD, FnMode, NUC
F1; SW (SWH), TD, FnMode, NUC
The total number of FID is TD1 as complex.
FnMode is set as States-TPP or Echo and Anti-Echo, etc.
NUC for F1 is set in parameter.
3D Acquisition (F3, F1, F2)
F3 is the direct detection dimension.
F1 is the 1st indirect detection dimension.
F2 is the 2nd indirect detection dimension.
F1 and F2 can be swapped in pulse sequences.
F3; SW (SWH), TD, FnMode, NUC
F1; SW (SWH), TD, FnMode, NUC
F2; SW (SWH), TD, FnMode, NUC

The total number of FID is TD1*TD2.
aqseq 312 or 321 modes are available in sequences which swap the acquisition order of F1 and F2 in 3D;
Pseudo-3D Acquisition (F3, F1, F2)
F3 is the direct detection dimension.
F1 is for aa array of parameters.
F2 is the indirect detection dimension.
As results, F3-F2 2D spectra are acquired inteleaved with parameter values in array.
F3; SW (SWH), TD, FnMode, NUC
F1; dummy, TD, FnMode, dummy
F2; SW (SWH), TD, FnMode, NUC

The total number of FID is TD1(# of array)*TD2. In aqseq 312, F1 is used for an array of parameters, so FnMode is QF and SW/NUC in F1 are not used.
Array parameters like vdlist, vclist etc. are used.
slice or rser2d command can be used to restore a series of 2D at diffferetn expno's.
Interleaved 2D Acquisition
F2 is the direct detection dimension.
F1 is the indirect detection dimension.
In sequence, F1 and an array of parameters are interleaved, so mutiple 2D are acquired.
Data structure look like pseudo-3D acquisition but recognized as 2D.
F1I is used as interleaved 2D mode in sequence.
The number of arrays are repeated in 2D acquisition, so TD1 is set as (TD1 for for 2D)*(number of arrays in F1I).
split can be used to restore a series of 2D at diffferetn expno's.