Before beginning work in the NMR labs, please observe the following safety rules.
1) Persons with medical devices such as cardiac pacemakers and prosthetic parts must remain outside the 5-gauss perimeter. The magnets generate strong magnetic fields that can affect operation of some pacemakers or harm implanted or attached devices such as prosthetic parts and metal blood vessel clips and clamps. Pacemaker wearers and wearers of metal prosthetics and implants should contact their physicians to determine any health risks.
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2) Metal objects must remain outside the 5-gauss perimeter. Strong magnetic fields surrounding a magnet attract objects containing steel, iron, and other ferromagnetic materials, which include most ordinary tools, electronic equipment, compressed gas cylinders, steel chairs, and steel carts. Unless restrained, such objects can suddenly fly towards the magnet, causing possible personal injury and extensive damage to probe, dewar, and superconducting solenoid. The greater the mass of the object, the more the magnet attracts the object. Only non-ferromagnetic materials should be used around the magnet.3) In the event of a "magnet quench," leave the area immediately, leaving the doors to the NMR lab open. A quench refers to a sudden appearance of gases from the top of the dewar. Sudden release of helium or nitrogen gases can rapidly displace oxygen in an enclosed space creating a possibility of asphyxiation. Do not return until the oxygen level returns to normal.
5) Do not exceed boiling or freezing points of a sample. A sample tube subjected to a change in temperature can build up excessive pressure, which can break the sample tube glass and cause injury by flying glass and toxic materials. To avoid this hazard, establish the freezing and boiling points of a sample before doing a variable temperature experiment.
CAUTIONS: Can cause permanent damage to equipment or data.
1) Cards with magnetic strips such as ATM cards, credit cards, and driver’s licenses, should remain outside the 5-gauss perimeter. Strong magnetic fields surrounding a magnet can damage the strip of magnetic media found on most credit cards, ATM cards, and similar plastic cards. Floppy disks and tapes are also susceptible to damage inside this perimeter. Many wrist and pocket watches are also susceptible to damage from intense magnetism.
2) Be very careful with sample tubes. Tubes are fragile and can easily break. The top of the sample tube can break off when the probe is removed. It is best to eject the sample before removing the probe from the magnet. Otherwise, use extreme caution when removing the probe if the sample is still in the probe.
3) Never operate high-power amplifiers with liquid probes. The NMR 400 wide bore has been equipped with high-power amplifiers for solids state NMR spectroscopy. Users should never operate these amplifiers with liquid probes. The high power available from these amplifiers (300- 1000W) will destroy liquid probes. Make sure to use appropriate high- power probe with the high-power amplifier.
1) NO Smoking in the NMR Facility. Smoke particles are the right size to enter and damage computer disk drives.2) Be careful with Food or Drinks in the NMR Facility. Spills can dirty keyboards (if you are lucky) or damage instrumentation
3) No unauthorized individuals or unescorted guests are allowed in the NMR facility.
4) No one with a pacemaker or metallic implant may enter the NMR facility.
5) The NMR facility door, should be kept locked shut when no one is present in the rooms. Make sure that doors to NMR lab, main lab and Room 419 are locked before leaving in evening, or at any time the area would be unoccupied.
6) No magnetic material, electronic equipment, large hardware, or tools are allowed near the magnet.
7) Before using any non-standard equipment or experimental setup the NMR Manager should be informed so that safety measures can be discussed and then implemented.
8) Individuals may not work alone when setting-up and/or performing non-standard experiments.
9) Only trained individuals should transfer the liquid helium and nitrogen to the instrument. Handling cryogens is dangerous and can cause serious burns.
10) When no probe is inserted into the magnet, covers should be placed over the magnet openings (this keeps out small objects, including magnetic dust).
11) If a sample tube breaks in the magnet, contact the NMR Manager immediately so the probe can be removed and cleaned. This will minimize probe damage.
12) Spectrometers are equipped with deuterium lock. It is advisable to have some deuterium in the sample, and generally samples are prepared by dissolving in deuterated solvents. If a deuterated solvent is not possible, a lock signal can be created by positioning a capillary tube with deuterated material inside the NMR tube. Deuterated solvents are never isotopically pure, so residual solvent peaks appear in the proton spectrum. Use high grade solvents, particularly with dilute samples. Many solvents are hygroscopic and will quickly absorb water from the air if not sealed. It is important that the melting point and the boiling point of the solvent be taken into account when an experiment at other than room temperature is intended.
13) Impurities- Paramagnetic or ferromagnetic impurities will lead to signal degradation and/or lock instability. Filter samples if necessary.
14) Sample length should be about 3 cm (.6ml). Overfilling wastes solvent and dilutes sample (decreasing signal strength). Underfilling makes shimming difficult and degrades resolution. Gradient shimming will work much better with a 0.6 mL sample! Make sure to eject the previous sample from the magnet before inserting your sample tube to the magnet.
15) The NMR data storage system has limited storage capacity and cannot provide long-term storage. Users are responsible to check on their disk usage and delete unwanted files or backup the important files to a more permanent storage medium such as CD.
16) Each individual is responsible for handling, labeling and storage of samples they bring into the laboratory. Samples from previous users will be stored in the egg crate inside the door of the left hand fridge.
17) Cellular telephones should not be used in or near the NMR lab. The RF fields that they generate while in use can interact with the RF circuitry of the spectrometer, degrading spectra
18) Hazardous samples may not be brought into laboratory without prior discussion of the handling and disposal procedures with the NMR manager.
19) Report all defective equipment to the NMR Manager (Deane McIntyre, Room 420).