vnmr cheat sheet by HC121106114811

VIEWS: 3 PAGES: 2

									                                                                             Underlined text indicates a button to be clicked
Sample Insertion and Setup
   1.   Log in, select a grant in the box that appears, and click the icon in the bottom task bar to open VNMR
   2.   Type e for eject (ensure you hear the air start flowing after typing e)
   3.   Find the spinner near the computer, insert sample, measure depth, and place in magnet
   4.   Type i for insert, the sample should slowly descend into the magnet
   5.   Type jexp1 to join experiment number one
   6.   Click setup and chose appropriate nucleus and solvent (ex. H1, CDCl3 or nuc,solv)
   7.   Click lock pars (except on the mercury) and wait for the computer to beep, click latest shims (wait for beep)
   8.   Click Acqi (note this button is in the top row, do not confuse it with the Acquire button in the bottom row)

Locking and Shimming
   9. In the box that appears, click lock
   10. Ensure that the spin is on (top left) and set to 20 (all the way down the bottom of the acqi window)
       --You will notice four different increments (± 1, 4, 16, 64) for all the rows of parameters in the bottom portion of
       the window. Place the cursor on the increment desired, left click = minus and right click = plus
   11. Turn the lock off (at the top)
   12. Maximize the lock power (2nd row) and lock gain (3rd row) by clicking +64 (right click)
   13. Adjust Z0 (1st row) by clicking ± 4 or 16 until you see something like a plateau                     or
       --Watch the wavelength as you adjust Z0. You want the wavelength to increase. Ignore changes in intensity.
   14. Once you have a plateau, turn the lock on (at the top)
   15. Decrease the lock gain until the lock level (displayed above the plateau) is ~60-80. If the lock level is bouncing
       (changes of more than 5), decrease the lock power until the lock level is stable (even if less than 60)
   16. Now decrease the lock power until the lock level ~30-50
   17. Click shim (up top). The goal of shimming is to maximize the current lock level displayed in the shim window
   18. Adjust Z1C by clicking ± 4 until the lock level is as high as you can get it. Click slowly, if clicking +4 makes the lock
       level decrease, click -4 until it starts to decrease again, and then click +4 once and you should have the max
   19. Now do the same for Z2C
       --If the lock level reaches 100 while shimming, return to lock and decrease the lock power and return to shim
   20. Continue going back and forth between adjusting Z1C and Z2C until you feel the lock level will not get any higher
       --It will reach a point where ±4 on both Z1C and Z2C will make the lock level decrease, continue with ±1
   21. Take your time with shimming, it is very important, as poor shimming will result in poor line shape
   22. Once shimming is complete, return to lock and ensure the lock level is 50-90. Adjust the lock gain if necessary
   23. Click close (top left)

Acquiring
   24. OPTIONAL: Now is the time to alter any parameters you wish to change. Type parameter=x, where parameter is
       what you want to change and x is the value you want. (ex. nt=64 or d1=5)
   25. Type ga to start the acquisition. Note the instrument status in the acquisition status box in the top right. One of
       the first things it will do is auto set gain. This step may cause an error with highly concentrated samples.
   26. If you see the status change from auto set gain to acquiring, you can continue. If it gets stuck on auto set gain
       (the status goes to idle without ever acquiring), you will see the following error: autogain failure, gain driven to
       zero, decrease pulse width. Type pw=pw/2 and then type ga to restart the acquisition.
   27. Label the spectrum by typing text(‘insert your label here’)
   28. If a 13C (or another nucleus) spectrum is desired continue to step 29, otherwise go to step 33
   29. Move to another experiment number (jexp2)
   30. Click setup, and chose the appropriate nucleus and solvent (ex. C13,CDCl3 or nuc,solv)
   31. Start the acquisition and label the spectrum with ga and text(‘….’)
   32. Return to the experiment with the proton spectrum (jexp1)

Processing
   33. Proton - to view spectrum type ds (if it is still acquiring in experiment one, wait until it is finished)
   34. If necessary (mainly on the VXR), click full to zoom out, and click and hold the middle mouse button and drag
       the mouse up or down to adjust the height of the peaks
                                                                          Underlined text indicates a button to be clicked
   35. Type aph to autophase the spectrum
   36. Click dscale (or you can type dscale) to show the chemical shift scale
   37. Find the reference peak (usually either the solvent peak, see the sheet next to the computer for the appropriate
       reference value, or TMS near zero)
   38. Left click on the left side of the reference peak and right click on the right side, now click expand
   39. Left click on the reference peak and type nl. This will move the cursor to the center of the peak.
   40. Once the cursor is on the peak, click ref. You will be prompted for the value, enter the appropriate chemical
       shift for the reference in ppm.
   41. Click full (or you can type f), and click part integral. You should see a green line, this is the integral (or area)
   42. Click resets and left click on both sides of every peak (or groups of peaks if some are close together). This must
       be done for every peak, including impurities, the solvent, and the reference peak(s).
   43. You should now see a solid green line over the peaks and a dotted green line over the baseline (or noise)
   44. Type bc cz, you should now see a solid green line with no resets and it should be flat for the baseline
   45. Click resets again. This time only left click around the peaks in which you are interested (ignore the solvent and
       reference). You may need to expand to resolve some peaks which are close together (see step 38)
   46. When all the peaks have been cut out, click box (or cursor) to end resets mode.
   47. Left click on a peak of known 1H amount (ie CH=1, CH2=2, CH3=3)
   48. Once the cursor is on the peak to be set, click set int, enter the appropriate number of protons for that peak
   49. Save the spectrum, type svf(‘insert_your_file_name_here’) (no spaces allowed in file names)
   50. Print (see printing section below)
   51. Carbon – type jexp2
   52. Type wft (if necessary, click full and adjust height, see step 35)
   53. Similar to proton, type aph, click dscale, and reference the spectrum (nl and ref)
   54. Click th (threshold) and move the yellow line with the left button so all peaks of interest are above the line
   55. Print (see below) and save (svf(‘…’))
   56. Exit (see Sample Ejection and Exiting below)

Printing: click main menu, display, and plot to enter printing menu
       --There are two main printing buttons: standard H1, and standard C13, click whichever is appropriate
       --You can also manually print by typing a combination of the commands for what you want
               pl – print spectrum                               pir – print integral values (type vp=12 first)
               pscale – print scale                              pltext – print text (label)
               ppf – print peak frequencies                      ppa – print text and limited set of parameters
               pll – print line list (gives list of frequencies) pap – print text and all parameters
       --the page command must be added at the end of any string of print commands for printing to being
               Typical example: vp=12 pl pscale pir pltext page (this is exactly what clicking standard H1 does)

Important Notes: the first time you log onto each instrument, you must do a few things in VNMR.
       --type custom and press enter, and type wysiwyg=’n’ and press enter
       --click main menu, more (all the way to the right in the second row), configure
                Now click select plotter until the screen shows that the proper plotter is selected (mercury-plot for the
                two mercury computers, and 107-plot for the VXR and Gemini). Do the same with select printer.
       --Also, to create new numbered experiments (you only start with one) click main menu, workspace, create new

Sample Ejection and Exiting
       Eject the sample using e (if necessary, stop the acquisition with sa), once you have the spinner out of the
       magnet, stop the air flow with i (leave the empty spinner on the desk), type exit to exit the program, and then
       exit the operating system (right click on the desktop or click exit in the bottom taskbar)

Staff: Director: Dr. Ion Ghiviriga – CLB108A, Engineer: Robert Harker – CLB106, TA: Russ Winkel
       After hours or on the weekend, please email nmr@chem.ufl.edu and rharker@chem.ufl.edu with a detailed
       description about which instrument you were using and what you were doing when the incident occurred. If
       you feel it would be unsafe for others to use the instrument, please click the small lock symbol in the taskbar.

								
To top