13C J-Modulation experiments (APT and DEPT) NMR Step by step
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C13 J-Mod (20 min. experiment)


In that APT  (or J-Mod experiment) the delay is adjusted such that the CH and CH3 have opposite phase
to Quaternary and CH2 type of carbons. The recycling delay is based on Carbon-13 relaxation time.
(There is an improved version of the APT which can be repeated with smaller pulse angle. For information see me)


 


  1. Press <F2> (new file) and enter your file name in the NAME box and click on the SAVE button. Your file name should have the following format:

  2. Use your initials in front of the file name (two letters) to ensure that we can identify the owner of the file. Next enter as a third character the first letter of the month and then the week number. After these four necessary characters, you can enter an underline character and any letters/numbers you wish. The file name must not contain any special characters like: !"#$>&/()=?`^*@_-¨., ' '}{][. And must not contain spaces.
    e.g. FSD2_C13 (this file name comes from user FS and was run on second week of december.
  3. Press <F5> to select the experiment. From the experiment list, select "1d_Jmod". This will recall a standard set of parameters for J-mod experiment (APT- Attached Proton Test) (CH and CH3 phased up, Quaternary carbons and CH2 pointing down.)
  4. Press <F6> to start the acquistion. (the receiver gain will automatically be adjusted). To view the acquisition window, type: acqu. Using the <Halt> key <F12> you can stop your experiment and transfer the data to disk for processing.

  5. If you have halted your experiment and wish to continue acquiring data, simply type go. The acquisition will start from the beginning but the data will be added to the existing experiment.
     
  6. When the acquisition is finished, press <F7> to process the data. (line broadning is set to 2 Hz, fourier transform, automatic phasing and automatic peak picking).

  7. You can use the manipulation button to scale and zoom the data. (As the manipulation of the spectra is identical to the proton spectra the description of the buttons will not be repeated here)
     
  8. Use the DP1 button to define the displayed zoom as the plot region.

  9.  
  10. Press <F8> to enter a title for the experiment. When you press the title's function key, a text editor opens up. Enter your text and click on the <save> command in the <file> menu.

  11.  
  12. If you want to view the plot before printing the data, enter the command: view. If the plot looks OK, quit the preview window and Press <F9>. The plot will contain the spectrum and peak picking, the title and the parameter list.

  13.  
  14. If you want to list the negatively phased peaks, simply type psign (peak sign) and select both.

C13 NMR DEPT135 (Disortionless Enhancement by Polarization Transfer): Step by step


In that DEPT-135  the last pulse on proton is adjusted to 135 degree such that the CH and CH3 have positive phase
while CH2 type of carbons are phased negative. As the magnetization is transfered from protons to their directly attached carbons, quaternary carbons are absent in the resulting spectra (deuterated solvents are behaving like quaternary carbons in that experiment and therefore are absent from the spectra. The recycling delay is based on Proton relaxation time.


 


  1. Press <F2> (new file) and enter your file name in the NAME box and click on the SAVE button. Your file name should have the following format:

  2. Use your initials in front of the file name (two letters) to ensure that we can identify the owner of the file. Next enter as a third character the first letter of the month and then the week number. After these four necessary characters, you can enter an underline character and any letters/numbers you wish. The file name must not contain any special characters like: !"#$>&/()=?`^*@_-¨., ' '}{][. And must not contain spaces.
    e.g. FSD2_C13 (this file name comes from user FS and was run on second week of december.
  3. Press <F5> to select the experiment. From the experiment list, select "1d_dept135". This will recall a standard set of parameters for the DEPT experiment (DEPT- Distortionless Enhancement by Polarization Transfer) with the proton pulse set on 135 degree. (CH and CH3 phased up, Quaternary carbons and CH2 pointing down.) This experiment is based on proton relaxation rather than C13 relaxation. Also the carbon are enhanced by proton polarization transfer: this means that quaternary carbons are not detected
  4. Press <F6> to start the acquistion. (the receiver gain will automatically be adjusted). To view the acquisition window, type: acqu. Using the <Halt> key <F12> you can stop your experiment and transfer the data to disk for processing.

  5. If you have halted your experiment and wish to continue acquiring data, simply type go. The acquisition will start from the beginning but the data will be added to the existing experiment.
  6. When the acquisition is finished, press <F7> to process the data. (line broadning is set to 2 Hz, fourier transform, automatic phasing and automatic peak picking).

  7. You can use the manipulation button to scale and zoom the data. (As the manipulation of the spectra is identical to the proton spectra the description of the buttons will not be repeated here)
  8. Use the DP1 button to define the displayed zoom as the plot region.
  9. Press <F8> to enter a title for the experiment. When you press the title's function key, a text editor opens up. Enter your text and click on the <save> command in the <file> menu.
  10. If you want to view the plot before printing the data, enter the command: view. If the plot looks OK, quit the preview window and Press <F9>. The plot will contain the spectrum and peak picking, the title and the parameter list.
  11. If you want to list the negatively phased peaks, simply type psign (peak sign) and select both.