1D Selective Tocsy

TOtal COrrelation SpectroscopY using gradient pulses
Bruker Avance AV 500

  1. Preliminaries
    Acquire a standard 1H NMR spectrum,
    from signing the log-book through processing.
    Optimize: td, sw, sfo1 (and optional/optimal: p1, d1)

  2. new expno
  3. new
    1. open a new experiment
    2. update the expno
    3. choose: 1D_seltocsy-bbo

  4. Update parameters
    AcquPar (ased)
    update: td, sw, sfo1, and ns
    (also p1 and d1, if available)

  5. determine spoffs2
    spoffs2 ("shaped pulse offset")
    is the selective part
    of 1D selective TOCSY;
    the irradiation frequency.

    spoffs2 is the difference in Hz between the center frequency (sfo1/o1/o1p) and the peak of interest.

    A crude way to set it:
    use the mouse to measure the difference between the middle of the spectral width (o1) and the peak of interest (to the left of the middle will have a positive sign, to the right of the center will have a negative sign).

    Here's an alternative, more exact method (better results):
    1. open the reference 1H spectrum from step 1
    2. type: sr o1
      (that is the letter o and the number 1)
    3. place the mouse on the center of the multiplet to be irradiated
      (spectral display properties should show the cursor information, if not, then right-click)
    4. write down the frequency (in Hz, with the positive or negative sign)
    5. return sr to zero, type: sr 0
      (that is the number zero)
    6. return to your new tocsy experiment number (from step 2) and update the spoffs2 in Hz with the correct sign

  6. One last bit
    1. Update the following acquisition parameters:
      d9 0.02 tocsy mixing time
      (start with 20ms and increment by 20ms to 120ms maximum)
      ns 8 (or a factor thereof)
      ds 2 (or 4)
    2. type: expt
      the experimental time should be approximately 1 minute, otherwise
      CHECK d9!!
    3. rga
    4. start acquisition (type: zg)

  7. Process and print
    Multiple display mode .md can be helpful for analysis.
    Use stacked plots in the Topspin plot editor for a nice summary of your results.
Report problems and bugs to Yael or Shifi - 3748