Nuclear Magnetic Resonance (NMR)
Nuclear Magnetic Resonance, abbreviated as NMR, is a technology used to identify or characterize chemicals or chemical mixtures. It is one of the most powerful tools for qualitative analysis of the composition and structure of various organic and inorganic substances, as well as quantitative analysis. Nuclear magnetic resonance (NMR) technology is widely used in drug synthesis, discovery of active components of natural medicines, chemistry of organic polymer materials and quality management of food and drugs.
Testing principle of NMR
The testing principle of the nuclear magnetic resonance spectrometer is that when the nuclear magnetic moment is not zero, the energy level will split when placed in a strong magnetic field, and the nucleus at the low energy level absorbs energy and jumps to a higher energy level under the action of external radio frequency pulses. When the external radio frequency pulse ends, these atomic nuclei that transition to high energy levels will spontaneously change to low energy levels, and the absorbed energy will be released in the process of transformation in the form of electromagnetic waves. The frequency of this electromagnetic wave is related to the chemical environment of the nucleus in the molecule. The chemical structure of the molecule is analyzed by measuring the frequency of the electromagnetic wave.
According to the NMR spectrum, it can be divided into 1H-NMR spectrum, 13C-NMR spectrum, fluorine spectrum, phosphorus spectrum, nitrogen spectrum and so on. Organic compounds and polymer materials are mainly composed of hydrocarbons, so 1H and 13C spectra are most widely used in the study of material structure and properties.
- Chemical shift→the chemical environment in which a proton is located
- Number of peaks→hydrogen number of adjacent groups
- Integral area→H number contained in its own functional group
- Providing C skeleton information
Our NMR laboratory instrumentation:
T,C&A Lab is equipped with three NMR spectrometers, which operate at the following frequencies:
- 400 MHz NMR
- 500 MHz NMR
- 600 MHz NMR
- 800 MHz NMR
- Determination of molecular structure.
- Study on the anisotropy of chemical shifts.
- Application of metal ion isotopes.
- Kinetic NMR study.
- Quantitative analysis of elements.
- Structural analysis of organic compounds.
- Surface chemistry.
- Discrimination and determination of isomers in organic compounds.
- Analysis of chemical structure of macromolecules.
- Study on the polymorphism of biomembrane and Lipid.
- Study on lipid molecular dynamics of lipid bilayers.
- Protein-lipid interaction in biofilm.
- Qualitative identification and structure analysis of crude oil.
- Chemical structure analysis of asphalt.
- Paint analysis.
- Pesticide identification.
- Food analysis.
- Drug identification.
- Can nuclear magnetic resonance spectra be measured for all elements in the periodic table?
- How to better show active hydrogen in H spectrum?
First of all, the spin quantum number of the measured nucleus should not be zero; second, the spin quantum number should be 1/2, because the nucleus whose spin quantum number is greater than 1 has electric quadrupole moment and the peak is very complex; third, the natural abundance of the measured element or its isotope is relatively high, if the natural abundance is low, the sensitivity is too low to detect the signal.
The hydrogen connected to O, S and N is active hydrogen. If you want to see active hydrogen, you must choose deuterated chloroform or DMSO as solvent.
The peak position of active hydrogen in DMSO is lower than that in CDCl3. Due to the influence of hydrogen bond, concentration, temperature and other factors, the chemical shift of active hydrogen will change in a certain range, and sometimes the action of intramolecular hydrogen bond will make the peak shape sharp.
In conclusion, T,C&A Lab can offer NMR services that can solve materials testing related problem. Finally, please complete the form to have an expert discuss your needs.
- Cao, Ruge, et al. Applications of nuclear magnetic resonance spectroscopy to the evaluation of complex food constituents. Food Chemistry 342 (2021): 128258.
Note: this service is for Research Use Only and Not intended for clinical use.
- Atomic Absorption Spectroscopy (AAS)
- Atomic Force Microscope
- Auger Electron Spectroscopy
- Electron Backscatter Diffraction
- Energy Dispersive Spectrometer (EDS)
- Focused Ion Beam (FIB)
- Fourier Transform Infrared Spectroscopy (FTIR)
- Gas Chromatography - Mass Spectrometry (GC-MS)
- Gel Permeation Chromatography (GPC)
- Glow Discharge-Mass Spectrometry (GD-MS)
- IGA Gas Adsorption System
- Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)
- Ion Chromatography (IC)
- Laser Ablation-Inductively Coupled Plasma Mass Spectrometer (LA-ICP-MS) System
- Nuclear Magnetic Resonance (NMR)
- Raman Spectrometer
- Rutherford Backscattering Spectrometry (RBS)
- Scanning Electron Microscope (SEM)
- Secondary Ion Mass Spectroscopy (SIMS)
- Thin-Layer Chromatography (TLC)
- Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS)
- Total Reflection X-ray Fluorescence
- X-Ray Diffraction (XRD)
- X-Ray Fluorescence (XRF)
- X-ray Reflectivity (XRR)