User guide for the NMR spectrometer AVA300

Transcription

1 1 User guide for the NMR spectrometer AVA300 Dear User! You are using a highly frequented NMR spectrometer, which has been installed in About spectra are measured here per year. Please respect the interests of other users and read the entire manual before using the spectrometer. Nevertheless, nobody is perfect and we are all learning from mistakes. Please report such cases immediately to the NMR department to avoid spectrometer downtime or even damage. Do not waste your time with trying to delete the traces of your activities. You will not be punished! On the contrary, your courage and responsibility can help tremendously in troubleshooting problems caused by your error. I. Safety precautions The superconducting magnet of NMR equipment produces strong magnetic and electromagnetic fields that can interfere with the function of cardiac pacemakers. Users of pacemakers and other implanted ferromagnetic medical devices are not allowed to enter the NMR room! Pregnant women and persons with non-ferromagnetic medical auxiliaries are required to contact the NMR department before using the spectrometer. The force that the magnetic field exerts on a ferromagnetic object (iron) may be very strong. Loose metal objects in the vicinity of the magnet can make sudden movements and be attracted to the magnet. This especially applies to very small ferromagnetic objects, which can be drawn into the magnet. They can damage the probe, are very difficult to remove, and will block the use of the spectrometer for a long time. The magnetic field can erase the magnetic media of USB-sticks, MP3-players, and mobile phones, disable credit and automated teller machine (ATM) cards, and damage analog watches. Please leave such items at the entrance of the room. The wall thickness of an NMR tube is about of 0.4 mm. Do not apply excessive force on when you close, open or insert the NMR tube into the spinner turbine. In rare cases, the superconducting magnet can spontaneously change from the superconducting to the normal state ("quench"). This transition causes an explosive vaporization of cryogenic substances from the magnet. In such case you are obligated to leave the room immediately and to inform the NMR department.

2 2 II. NMR sample preparation and injection 1. Samples for NMR analysis should be prepared in a defect-free 5 mm NMR tube. The tube cap must be on tightly to prevent evaporation of solvent while waiting in the queue. 2. The use of sealed or J. Young NMR tubes is prohibited. 3. Either 7 or 8 inch NMR tubes can be used and the tubes must have a quality according to the fieldstrength (e. e. 507-PP or higher). 4. Samples must be prepared using deuterated solvents. It is prohibited to use acids as the NMR solvent! 5. The optimal height of the liquid in the NMR tube is about 4.5 cm that corresponds to about 0.7 ml of the solvent. 6. The required concentration of an NMR sample depends on the experiment and the sensitivity of the observed nuclei. If possible, increase the concentration to improve the quality of the spectrum, especially for 13 C experiments. 7. The solution must be homogeneous. Precipitation and air bubbles impair the quality of NMR spectra and waste valuable measuring time. Solvent mixtures are avoided whenever possible. 8. NMR tubes must be clean outside. 9. Always wipe the NMR tube with Kleenex before inserting it into the spinner turbine. 10. Spinner turbines can be touched exclusively with clean, grease-free fingers at the upper edge (barcode). 11. The position of the NMR tube in the spinner turbine must be set using the red depth gauge. Slide carefully the NMR tube into the spinner turbine, plug the NMR tube along with the spinner turbine in the depth gauge and slide the tube gently to the bottom of the depth gauge. If you notice that the NMR-tube is loose inside the spinner then try another spinner or put your sample in another NMR-tube. Not correctly adjusted NMR tubes can lead to costly damage of the NMR spectrometer! 12. Place your NMR sample in the next free holder of the sample changer carousel. Please avoid the area of the light sensor to prevent the malfunction of automation. Use the holder number to register the sample in ICON-NMR. Note the different holder numbers of the inner and outer chains of the carousel (see the schema on the sample changer). Experiments are started according to the required measuring time not the holder number (day experiments from 7 to 19 o clock and night experiments from 19 to 7 o clock).

3 3 13. Please always check the proper adjustment of your NMR tube by comparison with other NMR samples (visual control). 14. Each NMR sample must be accompanied with a perforated note of reasonable size providing the username, the sample composition, and the holder number. III. General rules Please respect the interests of your colleagues. You are not the only ones who are in a hurry. ICON-NMR shows the available measurement time for the daytime and nighttime experiments as well as the expected duration of experiments. On the weekdays (from Monday to Friday) the pending queue of nighttime experiments is terminated at 7:30 o clock. The uncompleted experiments have to be resubmitted for the next night! 1. Warning: In case ICON-NMR is failed to start three consecutive NMR samples (incorrect number holder, inhomogeneous solution, too little solvent), the automation will be stopped for safety reasons and further measurements will not be carried out. 2. Please collect the measured samples as soon as possible.

4 4 IV. Referencing of NMR-spectra on AVA300 Proton-spectra: Because there is always a solvent peak in the spectra, the most established solvents can be used. 13 C-spectra: As for protons, with the exception of D2O: The SR-Value should be set to 9, P- and 19 F-spectra: In the case of these spectra, only solvents with a single solvent peak should be used. References are available for the following solvents: Solvent SR-Wert für 31 P SR-Wert für 19 F Aceton-d6-186,04-300,01 CDCl3-59, ,54 CD2Cl2-55,84-24,48 CD3CN - 162,62-344,92 C6D6-62, ,52 D2O - 80, ,65 DMSO-d6-129,83-130,76 CD3OD - 149,99-459,93

5 5 V) Short instructions for ICON NMR: 1. Choose your Workgroup at Change User. X Check in the window which is the next free holder in the sample changer. Meaning of the colours: Yellow: occupied, examination finished Pink: occupied, examination has been started Red: examination going on Green: next free holder Note: If all 120 positions have already been taken, do as follows: X 18 a) Look for the first free space in the window (beginning with position 1). b) Check at the sample changer if there is a tube at this position. If so, go on to the next yellow space without a tube. c) Delete the corresponding dates in the list. d) Insert your own sample under this holder number. 3. Open a line with a double click at status and enter the necessary dates for your examination: Holder: number of the holder Type: given Status: status of the sample (similar to 2.) Disk: given, is automatically generated Name: is automatically generated EXP. No.: automatically generated and incremented Solvent: choose the corresponding solvent Experiment: choose your examination 4. Examine once more whether your holder number in ICON-NMR and in the sample changer correspond. Then submit your completed examination request at the left side of the screen.

6 6 VI) Experiments and required concentration of the NMR solution: Name in the automation NS: Measuring range [ppm]: Concentration [mol/l]: Time for measurement (without shim!): 1 H rau_protonlf_16 NS ca. 0,025 about 2 minutes rau_protonlf_64 NS ,01 about 6 minutes 13 C{ 1 H} rau_c13cpd_256 NS about 15 minutes rau_c13cpd_1k NS 1k ,05 about 60 minutes Dept135 rau_dept135_64 NS ,15 about 4 minutes rau_dept135_256 NS ,05 about 15 minutes Dept90 rau_dept90_64 NS ,15 about 4 minutes rau_dept90_256 NS ,05 about 15 minutes 31 P{ 1 H } rau_p31cpd_64 NS ,10 about 3 minutes 31 P rau_p31_64 NS ,10 about 3 minutes 19 F{ 1 H } rau_f19cpd NS ,10 about 1 minutes 19 F rau_f19 NS ,10 about 1 minutes Par.: stands for parameter and is locked. Orig./Title: Enter your name, substance and concentration Pri.: display of day/ night-experiments, otherwise locked Time: display of net examination time. Add up to 8 minutes for lock and shim of the sample. User: display of the user name