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1H Sensitivity Test

PRELIMINARY SET-UP
Standard sensitivity test sample: 0.1% Ethylbenzene in Cloroform-d.
  • 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 H spectrum.
  • PARAMETER SET
    The calibration of the 1H sensitivity is performed using the a standard 1H parameter set that can be loaded by typing rpar PROSENS all(the pulse program is set to pulprog zg).

    MODIFY SPECIFIC PARAMETERS
    The test is usually performed using a sample spinning rate of 20 Hz.

    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.

    The basic parameter are set to:

    d1=60
    o1p=4
    sw=10.098
    td=32k
    aq=3.24
    ns=1
    ACQUISITION
    Start acquisition by rga and zg (the expected experimental time is displayed with the expt command).
    PROCESSING
    The recorded data is Fourier transformed with ft (or ef) and phase and baseline corrections are performed using apk and abs, respectively. Modify processing parameters if required from the ProcPars section or using the ased command. The signal to noise ratio (S/N) is determined on the intensity of quartet lines in the spectrum of the Ethylbenzene according to the equation:
     
    S/N=2.5*(height of quartet)/(peak to peak amplitude of noise)

    Automated S/N calculation is performed using sinocal.

    PLOT
    Use the TOPSPIN plot editor (xwinplot)
    OBSERVATIONS
    Good sensitivity can be obtained with good resolution and good lineshape only. The splitting between the two central lines of the methylene quartet shoulg go lower than 15% (using a lb of 1 Hz).
    See spectrum

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