T1 measurements

Inversion Recovery

  1. Preliminaries
    1. Sign the logbook (name and phone number)
    2. Login to the computer
        user name
    3. Open Topspin (double-click the icon)
        topspin icon
  2. Acquire a 1H spectrum
    1. Is the shimming okay?
    2. Does the sample appear as expected?
    3. Optimize the basic parameters (sw, o1p, td, ns)
    4. Calibrate the 90 degree pulse, type: pulsecal

  3. Create a new experiment number
  4. Change the pulse program
    pulse sequence

    type: pulprog t1ir1d

    that is an abbreviation for: T1 inversion-recovery 1D
    (as opposed to the pseudo-2D pulse program called, simply, T1ir)

  5. Check the phase
    1. Set d7 to zero seconds
      This will give a 270 degree pulse
    2. zg
    3. ft
    4. phase all the peaks up-side-down

  6. Find the zero-crossing delay time
    1. change d7 to one second
    2. zg
    3. fp (this uses the same phase set in the previous step)
    4. keep changing d7 and rerunning the acquisition until the peak of interest disappears - keep the same phase parameters each time
    5. double-check the null point using a properly set d1

  7. Calculate T1
    1. T1 = 1.44 * d7(zero-crossing)
    2. For qNMR use aq + d1 > 5 * T1

  8. Report problems and bugs to Yael or Shifi - 3748