| Use: | Invaluable tool for determining the molecular structure of both large and small molecules and is increasingly used to create three-dimensional images of density or composition distribution in homogeneous materials. Primarily used as a research tool. |
Description:
Nuclear magnetic resonance (NMR) spectroscopy is the absorption of radio frequency (RF) radiation by a nucleus in a strong magnetic field. Absorption of the radiation causes the nuclear spin to realign or flip in the higher-energy direction. After absorbing energy the nuclei will re-emit RF radiation and return to the lower-energy state. The energy of an NMR transition depends on the magnetic field strength and a proportionality factor for each nucleus called the magnetogyric ratio. The local environment around a given nucleus in a molecule will slightly perturb the local magnetic field exerted on that nucleus and affect its exact transition energy. This dependence of the transition energy on the position of a particular atom in a molecule makes NMR spectroscopy extremely useful for determining the structure of molecules.
Analytes:
8. Radionuclides
Media:
| Soil/Sediment | Water | Gas/Air |
| BETTER | BETTER | BETTER |
| Selectivity: | Technique measures the contaminant directly. |
| Susceptibility to Interference: | Medium. |
| Detection Limits : | 500+ ppm (soil); 100+ ppm (water). |
| Turnaround Time per Sample: | Minutes. |
| Applicable To: | |||
| Screen/Identify | Characterize Concentration/Extent | Cleanup Performance | Long-Term Monitoring |
| BETTER | BETTER | BETTER | BETTER |
| Quantitative Data Capability: | Data become quantitative with additional effort. |
| Technology Status: | Commercially available technology with limited field experience. |
| Certification/Verification: | Technology has not participated in CalEPA certification and/or CSCT verification program. |
| Relative Cost per Analysis: | Mid-range expense. |
Limitations:
ASTM Standards/EPA Methods:
No applicable ASTM standards or EPA methods are cited for this technology.
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