Operating Instructions for the Gemini 200 for Proton Analysis

1. Turn on the CRT screen. The screen should display a Varian graphic. Type DG if the graphic is not displayed.
2. At the login prompt type your login name and the password. Regardless of the operating mode the typical NMR experiment takes the following steps.
     A  Prepare the sample and consideration in selecting a solvent.
     B. Log into the system as current user (Type your login name and password.),
     C. Insert the sample into the magnet,
     D. Enter the sample description,
     E. Select mode, set up (lock and shim) and run the experiment,
     F. Process and Print data, [There is also software to save the spectra on a floppy and priint from NMR SpecManager.]
     G. Remove test sample and return standard to the magnet obtain lock signal, and
     H. Sign out or use the Exit menu.

3. Turn the lock dial to the off position
4. Remove reference sample from the magnet by gently depressing the air valve on the left leg of the magnet. Lift the reference straight out to avoid breaking the glass tube. Place the sample in the holder with the collar up. (Look at the drawing on the leg of the magnet.)
5. Insert test sample
     A. Place sample tube into the collar and adjust the level relative to the pattern on the right leg of the magnet. Make certain the sample never goes below the bottom mark.
     B. Inset the sample and collar into the magnet and apply a gentle air pressure by depressing the air valve which will let the sample float down into the probe. Never drop it in.
6. The sample should be spinning about 15 rpm. Normally it is not necessary to adjust the air flow but it can be adjusted by turning the valve counter-clock wise to increase the spin rate. Get help if there is a problem. No adjustment is normally required.
7. Turn lock on. If it does not lock quickly (about 30 seconds) try turning to auto-lock (wait) and then back to lock. Or recall standard files.
     A. Type LK to open the lock screen. Make certain the sample is spinning. The green light on the            NMR leg and the top of the lock screen should say "Spinning".
     B. Turn the lock off with the PF3 button, do not adjust Z0 until the lock is off.
     C. Adjust Z0 with the black knob underneath the monitor. Adjust Z0 so the lock signal displayed is a standing wave. You may need to increase the Lock Power (up to a value of 30) and/or the Lock  Gain (up to a value of 30) or decrease depending on the instrument and sample.
     D. To lock the signal, push the PF4 button.
     E. To obtain the Shim Screen type "S" plus a carriage return
     F. When adjusting any of the shimming parameters, the goal is to maximize the lock signal. You can tell this by looking at the two-vertical bars on the screen. One is labeled "1X" and the other "5X". When the colored indicator is at it highest point in the bars, then you can go on and adjust the next parameter. Each parameter affects the lock signal. As a general rule you do not want to have the "1X" vertical bar pegged out. Reduced the Lgain if it is pegged. Start shimming your sample by adjusting the Phase, Lpower, and Lgain. Push the PF5 key.
     G. Adjust the Phase with the knob under the "Phase"
     H. Push the PF1 Key
      I. Adjust the Z1C by turning the knob under "Z1C".
      J. Go back and readjust the Z1C parameter, then the Z2C, then the Z1C, then the Z2C, until the lock signal is maximized.
     K. Push the PF5 key and adjust the Phase again. Turn down the Lpower if the "1X" indicator is greater than 50% and adjust the phase.
     L. Push the PF1 key and adjust the Z1C, Z2C; keep adjusting the Z1C and Z2C until you are confident the lock signal is maximized.  Maximize the shim homogeneity by adjusting dials starting with the coarse adjustment and working clockwise. The range should between 60-80. It may be brought into this range by adjusting the fine gain and fine power adjustments.
9. To acquire data (Taking Spectra):
     A. Check parameters. For CDCl₃: TN=1.75, NT=16 or type RT(NEWLIB.H1PED) which give standard 1H (CDCl₃) parameters.
     B. Type GA. While instrument is collecting data you may enter text to identify the sample by typing "TEXT(`....')". Note you must use both parenthesis and single quote marks. To stop acquisition type /ACQ.
     C. Once the data is acquired, you may remove the sample from the instrument and insert the next sample or the reference. The instrument is always left with a reference in the probe. The spectrum will appear when processing is complete, or use the DS command to display the spectra.
10. To process the spectrum:
     A. To set TMS as the reference type SP = -20, DCR. Line up the cursor on the TMS peak. Then           type RL, SP = -10. Adjust the vertical scale with VS.
     B. To phase spectrum there are several choices.
          a. First INT, LT (LVL = 0), X10. This will display your integration and an enlarged spectrum. You may visually inspect the phase and adjust it with the RP and LP dials. D10 reduces spectrum to normal.
          b. APH is autophase and is useful if the spectrum is badly out of phase.
          c. Finally, you may type D2CR and place the cursors on the CDCl3 and TMS peaks. Then type SET. Adjust the phase and type DS.
11. Once the spectra has been taken type WFT APH F (for Weighted Fourier Tranform, AutoPhase, and Full Spectrum)
     A. Reference the spectra by pushing the PF3 key twice to get two red line cursors. Place one cursor on each side of the reference peak using the knobs under "C R" or "C L" for the right and left cursor. Push the PF4 key to expand the spectra between the two cursors.
     B. Push the PF3 key twice so to obtain only one cursor. Use the appropriate knob to move the cursor to the center of the reference peak. Type NL RL (for nearest line reference line).
     C. To see the whole spectrum type F and a carriage return. Are there peaks past 8.5 ppm.
12. To print the spectrum:
     A. Setup by typing WP=9P SP.5P (for width plot and start plot)
     B. Integrate the spectrum: Type INT CZ (for integrate connect the dots) To cut the spectrum press PF3 to bring up the cursor, move the cursor to where you want to cut, and then press PF7 to cut the integration. Press PF7 again to bring back the rest of the integration. Move the cursor to the next place you want to cut and press PF7. Move the cursor to the other side of the peak and press PF7 until you are done cutting the spectrum.
     C. Labeling Peaks: Press PF6 to bring up the horizontal threshold cursor. Using the knob under "TH" move the horizontal cursor so that all the peaks you want labeled are at or above the threshold cursor. Type DPF (for Display Peak Frequencies)

There are a few macros that print the spectra and scale: PN1 or PN2. The former is a macro that gives the following commands PL, PLHEAD, PSCALE, PPF, PAGE. While PN2 is for the following: PL, PLHEAD, PSCALE, PAGE. 

There is also software to save the spectra on a floppy and priint from NMR SpecManager.

                 Some Gemini Macro Keys

1. Use a concentrated sample.
2. Change the parameter configuration setup values.
     The following table shows the old values now being used to run carbon and the suggested values. Please try the suggested values. The suggested parameter setting are stored and can be recalled with: RTP(Jerry) Other benefits

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