NMR Operating Procedures

NMR Operating Procedures

**********IMPORTANT PRECAUTIONS**********

a.If there is a problem with the instrument, please do not attempt to fix it. Call for instructions using the telephone or pager numbers at the bottom of the page.
b.You must be certified by the NMR facilities manager to independently operate the spectrometers.
c.You are NOT allowed to touch the probe, connect or disconnect any electronic cables.
d.You must follow the sign up and log out rules.
e.You should save your fid on the hard drive and transfer them to the Mac as soon as possible. Files that have been saved on the hard disk will be deleted periodically. An announcement will be made when this is going to occur, but it is your responsibility to insure your data is backed-up.

Step 1 -- Change sample (remove the STANDARD):

If you see a menu on the screen, type:

>X move into the command mode (with cursor >)
>EJ type EJ keys to eject the sample out of the magnet
<return> type return to let your sample drop into the magnet
The spin rate should be between 15-25, if it is not, type:
>AA adjust the spinner air flow using the knob on the keyboard

Step 2 -- Obtaining a Lock on your sample
(adjustments are made using the knob on the side of the keyboard):

>NS to select the desired solvent
>LD to view the lock display signal
S to toggle to swept display mode
G to adjust the signal gain power (CDCl3 = 200)
O to adjust the offset and move the signal to the center of the display
<space> hit the space bar to have a dual display of the lock signal
P to adjust the phase to a symmetric dual display
<space> hit the space bar to go back to the single display of the lock signal
S to toggle to meter display mode
L to select lock fast
G to adjust the meter to 50%

Step 3 -- Shimming the magnetic field on your sample:

While you are still in the LD routine, type:

K to manually shim lock signal
1 to shim Z1
2 to shim Z2
3 to shim Z3

Repeat shimming Zl and Z2 until a maximum lock gain is achieved, if the meter level goes off scale reduce the gain power by typing G and reduce the power with the knob on the right side of the keyboard. You may re-activate the shim controls by pressing 1 or 2. Once Z1 and Z2 are adjusted you may adjust Z3*, then type:

<return>
L to select lock slow
<return> to go back to command mode

*Do not adjust any other shimming functions unless given permission.

Step 4 -- Select experiment and set the parameters for 1D NMR spectrum:

>ME to go to the main menu
1 type 1 to select the #1 sub-menu: " 1. Exchange sample 'Examine/ current parameters"

Under the #1 sub-menu, type:

8 to select the default 1H one-pulse experiment,
 or
9 to select the default 13C one-pulse experiment
X to go back to command mode

Step 5 -- Setting the spectral window (optional):

>SG automatically set receiver gain
>NA set the number (#) of scans to 1
>ZG acquire one scan
>FT transform the scan
>ZO zoom the spectrum
F enter Fl and F2 for your spectral width, remember to enter "P" after the values
^E expand and display the selected region
W define your spectral window (width)

Step 6 -- Data Acquisition:

>SG to automatically set receiver gain
>NA to check the number (#) of scans (default NA =8)
 
When you are sure that the experiment and the parameters are set up properly, you can start to accumulate your data by typing:
 
>ZG to zero the memory of current block and acquire data (stores the data in the RAM for later storage on the hard drive with the SA command)
 
To save data on hard drive:
 
>SA to save data on hard drive
>File.name up to 6 characters and 3 extension
>comment up to 16 characters and spaces
<return>
 
You may also use the following commands to acquire your data. This method will allow you to save your data automatically at the end of the experiment.
 
>GS stores the data to the hard drive when the experiment is finished or stopped with the ^Q command
1<return> how many experiments, normally only 1
>File.name up to 6 characters and 3 extension
>comment up to 16 characters and spaces
>Y yes to auto-replace
 
To stop your experiment type:
^Q stop the acquisition at any time

Step 7 -- Data Processing, Plotting and Storage:

A. To process FID, type:
 
>LB set line broadening factor for EM, LB = 0.0 for 1H, LB=1 for 13C
>BC perform base line correction
>EM apply exponential multiplication on FID
>FT execute Fourier transform
>AP carry out automatic phase correction
>^F display full spectrum. (^F = hold control key, then F)
 
B. To zoom (or select) a part of the spectrum, type:
 
>ZO to zoom the spectrum
-><- type "-><-" key, and use the knob to select a region or type
F to enter Fl and F2, remember to enter "P" after the value
^E to expand and display the selected region
 
C. To plot spectrum, type:
 
>XY to define plot orientation on paper: XY = 0 for long plot, XY = 3 for short one-page plot
>CM to define plot size: 20 x 15 for XY = 3, 30 x 15 for XY =0
>YS to scale the tallest peak in the spectrum region to CM height
 
To select another peak as full scale use the following method.
 
>PP Peak Pick
K move the cursor to the peak you want to be at full scale
P
>PX to plot spectrum and axis (you may use the commands PL and LC for a full plot with the parameters)
 
D. To integrate the peaks, type:
 
>ID to go to integration routine, you will see red line
^R to reset (or to zero) integral breakpoints
S to scale the integral automatically
I to increase the integral scale
D to decrease the integral scale
-> type arrow keys and using knob to adjust red line to be parallel to the base line
P=5 to set and print integral 5mm above the base line to set and print
P=13 integral to 13cm high
<return> to get out from ID sub-program
 
E. To label peaks, type:
 
>MH to set minimum peak height for peak picking
<return> to execute MH
y to use a Lorentzian function
y to use the corrected value
 
>ZP to label each peak defined by MH command
L to label a peak
<space> to skip labeling a peak
<return> to get out from ZP at the end of labeling,
OR
Q to quit labeling at any time
 
F. To save data (HD or spectrum) on a floppy disk using disk drive #2 as an example:
 
>WD to designate which disk drive to use
SA=2 to designate floppy drive #2
SB=0& to get out of the WD routine
>SA to save data to floppy drive #2
file name to name your file (e.g., BH.001)
comments to add comments (e.g. Benzene 1H ~)
<return> to execute SA, (the light on drive #2 will turn on)
 
G. To get data from floppy or hard disk:
 
># to chose a block # in which to store and process data
>ZER to zero the current block
>WD to designate disk drive: 0 for hard drive, 1 or 2 for floppy
>GA to get the data into the current block
file.name name of the file you wish to retrive
<return> to execute GA
 
If you are in some kind of trouble, try the following Control Keys before considering re-booting the computer:
 
^O to abort current operation
^Q to stop data acquisition in progress
^C to abort everything
^P to abort plotting (need to press Clear on plotter several times to reset the plotter).

**********IMPORTANT FINISH UP**********

a.Lock and shim on the standard (CDCl3).
 
b.Reset the spectrometer to default value (>ME, 1, 8).
 
c.Recall the standard shims from the shim library
 AH to enter the shim library
 L to list the shim files
 <return> (hit return until you see the shim file chuck)
 L to load the chuck shim file
 X to exit the shim subroutine
 
d.Make sure you have saved your data or moved it to the MAC or PC (if you want keep it).
 
e.Logout and clean-up your mess. Note any problems in the log book before you leave. You may also send an E-mail message reporting the problem

Useful Phone Numbers

Dr. Charles AndersonOffice: x3-2728 (Fleming 302)
  E-mail: shiulong@bayou.uh.edu

The following are to be used in an emergency, only
if you are unable to get hold of the NMR manager.

Larry Simsx3-2798 (Fleming 305)
Randy Wilkinsx3-2750 (Fleming 14)
Professor Xiaolian Gaox3-2805 (53-SR1)