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2D 1H-13C HSQC using presaturation
(phase sensitive)

PRELIMINARY SET-UP
  • Insert the sample (ij).
  • Choose the solvent deuterium signal with the lock command
  • Tune and match the probehead (wobb or atma if required).
  • Optimize the shim procedure (read an optimized shim file with the rsh command or performs a gradshim if required).
  • Record a conventional 1H spectrum with presaturation. Note the o1p and SW values to optimize spectral widths in the corresponding 2D experiment.
  • If required, record a 1H-decoupled 13C spectrum. Note the o1p and SW values to optimize spectral widths in the corresponding 2D experiment.
  • PARAMETER SET
    Create a new dataset (new) and read the standard BRUKER parameter set (rpar) to record a 2D phase-sensitive 1H-13C HMQC spectrum using presaturation with rpar HMQCPHPR all (the pulse program hsqcphpr can be visualized in the PulsProg section or with the edcpul command).

    MODIFY SPECIFIC PARAMETERS
    It is generally recommended that HMQC experiments be run without sample spinning. Update the corresponding pulses and power levels in the acquisition parameters according to the selected solvent/probehead parameters by executing the getprosol command (pulses and power levels must be correctly set by the edprosol command). If required, any acquisition parameter can be modified manually or in the AcquPars section.

    Otherwhise, the required acquisition parameters can be displayed with the ased command. Modify the following parameters accordingly:

    Inter-pulse evolution period (d4=1/(4*cnst2)): Optimized with cnst2=145 Hz

    Set o1p on the solvent resonance and check for the power level (try pl9=55-60dB) and the duration (d1=1.5-2s) for an efficient solvent presaturation.

    Minimum number of scans are ns 4 and ds 16

    ACQUISITION
    Start acquisition by rga and zg (the expected experimental time is displayed with the expt command). Careful optimization of the solvent-dependent o1, d1 and pl9 parameters can be performed by minimizing the FID in gs mode.
    PROCESSING
    Process the recorded data with xfb. By default, SI2=SI1=1K and pure cosine squared sine window functions (WDW2=WDW1=QSINE) are applied to both dimensions (SSB2=SSB1=2) using MC2 (TPPI, States-TPPI ...) as defined in FnMODE.

    Phase correction in the F2 dimension is first accomplished taking the first 1D serial file (type rser 1, correct the phase in the TEMP file, and store these values before come back to the 2D data). Phase correction in the F1 dimension is automatically achieved by executing xau calcphinv

    Linear prediction can optionally be applied in the indirect F1 dimension.

    PLOT
    Use the TOPSPIN plot editor (xwinplot)
    OBSERVATIONS
    It can be advisable to store all acquisition and processing parameters (with the command wpar) to be used later.

    Both acquisition and processing steps can be performed using predefined automated AU programs. In this case, start data acquisition with the xaua command (the program executes the AU program defined in the acquisition parameters AUNM (au_getlinv)) and the data can be automatically processed and plotted with the xaup command (the program executes the AU program defined in the processing parameter AUNMP (proc_2dinv).

    This experiment can also by recorded in full automation mode using macros (edmac), BUTTON-NMR (buttonnmr) or ICON-NMR (iconnmr)

    OTHER RELATED VERSIONS
    Phase-cycle inverse experiments
    Gradient-enhanced inverse experiments


    Written by Teodor Parella
    Copyright © 1998-2008 BRUKER Biospin. All rights reserved.