- Published: Sunday, 01 March 2020 20:30
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Earth-field NMR relaxometer for scientific laboratories
The device allows to obtain high-resolution J-spectra of phosphorus, fluorine and silicon-containing liquids, as well as organic with 13C natural content. The device allows measuring relaxation times T1 and T2 of liquids in the Earth’s magnetic field, as well as T1 in the polarization field (up to 100 G = 0.01 T).
The device contains two sensors to neutralize the influence of fluctuations in the Earth's magnetic field
The device has a thermal stabilization system.
The device provides for the possibility of long-term accumulation of the NMR signal for detecting in the spectrum of lines from J-coupling interaction of protons with isotopes having a reduced natural content (for example, 13C).
Earth-field NMR spectrometer-relaxometer for training laboratories
The device is designed for laboratory work in universities. The device allows you to get acquainted with the principles of recording NMR signals, in particular in the earth's field:
Observation of the J-spectra of phosphorus, fluorine, and silicon fluids
Measurement of relaxation times T1 and T2 of liquids in the Earth’s magnetic field, as well as T1 in the polarization field (up to 100 G = 0.01 T)
Works developing the professional skills of students:
Fine tuning the input circuit to the NMR frequency to obtain the maximum signal
Shimming the earth's field in the working volume
Search for an NMR signal with a small signal-to-noise ratio
The main characteristics of both devices:
Range of working fields 20-50 mT (depending on the coordinates of the device)
NMR frequency 1200 ÷ 2700 Hz
Sample volume 50 ÷ 150 ml
Registered signals from 1H and 19F cores
Sizes for the sensor 200X200X400 mm
Examples of J-spectra obtained on the working model of the device:
Fig. 1. The spectrum of 2,2,2-trifluoroethanol. The sensor is tuned to the proton frequency (blue spectrum), to the fluorine frequency (red spectrum).
Fig. 2. The spectrum of polymethylsiloxane . The spectrum reduced by 25 times (blue) shows the comparative value of the proton main line relative to the value of the lines of interaction of protons with 29Si
Fig. 3. The spectra of trimethylphosphate (left) and triethylphosphate (right)
Photo prototype training NMR spectrometer: