|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.|
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.
|Selectivity:||Technique measures the contaminant directly.|
|Susceptibility to Interference:||Medium.|
|Detection Limits :||500+ ppm (soil); 100+ ppm (water).|
|Turnaround Time per Sample:||Minutes.|
|Screen/Identify||Characterize Concentration/Extent||Cleanup Performance||Long-Term Monitoring|
|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.|
ASTM Standards/EPA Methods:
No applicable ASTM standards or EPA methods are cited for this technology.
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