One of the most powerful scientific instruments used to study the molecules of life
—and the only machine of its magnitude in the state of Texas—was delivered
in January (2003) to the University of Houston.
Features Diagram Attentions Experimental Types
Experimental Steps Exchange Probes Turn off and on Spectrometer
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Ultra-stabilized magnet of 18.8-Tesla magnetic field strength. The proton frequency is 800 MHz. The temperature of liquid helium in the magnet is reduced to ~2.0 K from 4.2 K using BMPC (Bruker Magnet Pump Control system). |
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Three radio frequency channels with 2H decoupling of 20 Watts. The powers of 1H and two broadband channels are 100, 500 and 500 Watts, respectively. |
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70 Gauss/cm z-axis pulsed field gradient (PFG). |
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Three probes: |
TCI: three-channel inverse CryoProbe (1H/13C/15N)
TXI: three-channel inverse Room Temperature Probe (1H/13C/15N)
QXI: four-channel inverse Room Temperature Probe (1H/13C/15N/31P)
1. NMR spectrometer is very expensive, please run experiments as efficiently as possible.
2. Once you hear the sound (the sound of air flow) from magnet after you press the LIFT ON/OFF button on BSMS keyboard, you can insert spinner with your sample into magnet, otherwise you may break probe.
3. 120dB of power level corresponds to zero output of radio frequency power and -6dB of power level corresponds to maximum output. In order to protect probe, please don’t set the power level to a value less than specified values. You should be very careful when you change pulse widths and power levels.
4. When you manually tune and match probe, you should be very careful and don’t turn screw fast, otherwise you may break probe.
5. Please fill in log book on time and accurately.
6. You can always get help from the manager.
TCI CryoProbe (1H/13C/15N with 2H-decoupling):
All multi-dimensional 1H or 13C-detected multiple-resonance NMR Experiments
TXI Room Temperature Probe (1H/13C/15N with 2H-decoupling):
All multi-dimensional 1H-detected multiple-resonance NMR Experiments
QXI Room Temperature Probe (1H/13C/15N/31P with 2H-decoupling):
Besides the experiments being performed with IXI probe, NMR experiments related to 31P can be performed.
1.Type in login and enter your password to login the computer.
2.To enter the NMR software, type in xwinnmr in a shell.
3.To get a data set similar to your experiment, click File button, click search button, select a data set, and finally click Append button and Apply button.
4.To change the name, expno and user of the current data set, type in edc command. In the popped dialog, change the name, expno and user. Finally click the save button.
5.Insert your sample tube into spinner and adjust the position of the sample tube in the spinner with depth gauge.
6.Press LIFT ON/OFF button on BSMS keyboard, once you hear the sound (the sound of air flow) from magnet, you can insert the spinner with your sample into magnet. Then press LIFT ON/OFF button again. If your experiment takes long time, please place the cap on the up mouth of magnet.
7.Type in edte command to change the temperature of your sample. After the temperature is stable, you can perform the following steps.
8.Type in lock command to get lock signal, then in a popped window choose your solvent.
9.Type in A command to switch to acquisition window. Type in atmm command to remotely tune and match TXI probe. For QXI probe, you have to manually tune and match it.
10. Do manually shimming to get lock signal level as high as possible. Then type in gradshim command to shim automatically.
11.Type in gpro command to get default values of power levels and pulse widths.
12. To calibrate parameters, such as p1, type in paropt command and input proper initial value, increment and number of steps.
13. Type in zg command to start acquisition.
14. Type in efp command to process your data and get your spectrum.
15. To plot your spectrum, type in edo command to select an appropriate plot template in layout parameter. Then type in xwp command, modify related parameters and click plot button.
I. Taking out a probe (TXI)
1. Lift out your sample from magnet.
2. In XWINNMR, type in edte command, click turn off button in edte dialog.
3. Disconnect the cold gas tube from probe.
4. Disconnect all cables from probe.
5. Alternatively loosen two screws under probe. Slowly lower down probe and finally place it into a hard paper box.
II. Installing a probe (QXI)
1. Slowly insert QXI probe and alternatively fasten two screws under probe.
2. Connect all cables. If nucleus P-31 is detected, take away the filter for 13C between pre-amplifier and probe.
3. Connect cold gas tube to probe.
4. In WIN-NMR, type in edte command and click turn on button in the edte dialog.
5. Type in edhead command. In edhead dialog, choose QXI probe, click defines as current probe button, and finally click Exit button.
6. Type in edprosol command, confirm the pulse widths and power levels were all changed to fit the QXI probe.
7. Type ii (initialize interface) a few times.
8. Type in rsh command and choose appropriate shimming file.
I. Turn off spectrometer
1. Type in edte command, click off button in edte dialog.
2. In a shell, type in telnet spect, login in as root (it doesn’t need root password), type in init 5.
3. Kill all jobs in xwinnmr.
4. Exit xwinnmr and close all windows.
5. Shut down computer. Turn off BCU05.
6. Turn off two power amplifiers. Finally press the red button on front of console.
II. Turn on spectrometer
1. Press the green button on front of console. Fingers touch console frame a few times to discharge, then turn on the two power amplifiers.
2. Turn on computer and login.
3. Type in xwinnmr command in a shell to start NMR software. Type in ii command a few times to initialize interface.
4. Turn on BCU05.
5. Type in edte command to change temperature.
6. Type in rsh command in xwinnmr, in a popped dialog click Load LOCK Param at the bottom of the popped dialog and click an appropriate shimming file.
7. Type in lock to get lock signal.