scholarly journals Experiment on determination of ethanol chemical shift and concentration of ethanol solution based on nuclear magnetic resonance instrument

2020 ◽  
Vol 213 ◽  
pp. 01026
Author(s):  
Xinyi Liang
Keyword(s):  
Aqueous Solution ◽  
Nuclear Magnetic Resonance ◽  
Relaxation Time ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Copper Sulphate ◽  
Ethanol Solution ◽  
Ethanol Content ◽  
Ethanol Aqueous Solution ◽  
Nuclear Magnetic

In this designing experiment, a nuclear magnetic resonance instrument was used to study the chemical shift properties of ethanol based on the principle of magnetic shielding effect. At the same time, the nuclear magnetic resonance method was used to study the transverse relaxation time and signal strength of ethanol aqueous solution in the range of 5%to 40%. The relationship between different mass fraction of ethanol-aqueous solution and nuclear magnetic resonance signal intensity, relaxation time and solution concentration were analysed. According to the results, due to the limitation of experimental instruments, no regular changes were observed. The results show that the addition of copper sulphate can increase the ethanol content and the effect of the ethanol content on the lateral relaxation time: the ethanol content varies between 5% and 40%, and the lateral relaxation time changes from 8.42ms to 40.35ms.According to the experimental results, the empirical formulas of the concentration and lateral relaxation time of ethanol aqueous solution with fixed amount of copper sulphate were fitted. Using this relationship, the NMR measurement of the concentration of ethanol-water solution can be achieved, which provides a new method for the convenient and accurate measurement of the concentration of ethanol solution.

A Carbon-13 Nuclear Magnetic Resonance Study of Chlorinated and Polyol Analogs of Glucose and Related Oligomers

1975 ◽  
Vol 53 (7) ◽  
pp. 1030-1037 ◽  
Author(s):  
Pierre Colson ◽  
Keith N. Slessor ◽  
H. J. Jennings ◽  
Ian C. P. Smith
Keyword(s):  
Aqueous Solution ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Nuclear Magnetic Resonance Study ◽  
Substantial Decrease ◽  
Magnetic Resonance Study ◽  
Carbon Dissolution ◽  
Nuclear Magnetic

Complete assignments of the carbon-13 n.m.r. spectra of the following compounds in aqueous solution are presented: 6-chloro-6-deoxy-D-glucose, 6-O-methyl-D-glucose, ribitol, glucitol, 4-O-methyl-glucitol, maltose, maltitol, 6,6′-dichloro-6,6′-dideoxymaltose, 6′-chloro-6′-deoxy-maltose, isomaltose, isomaltitol, and 6′-chloro-6′-deoxyisomaltose. Some earlier assignments for maltose are reversed. Chlorination on the exocyclic carbon of the glucopyranose ring usually results in a substantial decrease in the chemical shift of the substituted carbon (−17 p.p.m.) and the next-nearest carbon (−1.2 p.p.m.); methylation leads to an increased chemical shift for the contiguous carbon (+10 p.p.m.) and only small changes for other carbons in the molecule. The response to 4-O-methylation in glucitol is opposite for C-3 (+0.7 p.p.m.) and C-5 (−0.8 p.p.m.) demonstrating that response of a particular carbon to substitution at a neighboring carbon depends upon the configuration of the particular carbon. Dissolution of these compounds in pyridine results in a bunching together of resonances which makes unambiguous assignments very difficult. The data for this series of compounds are useful in assigning the more complex spectra of microbial polysaccharides.

NUCLEAR MAGNETIC RESONANCE STUDIES: IX. THE CHEMICAL SHIFT OF THE FORMYL PROTON IN ALIPHATIC ALDEHYDES

1966 ◽  
Vol 44 (1) ◽  
pp. 45-51 ◽  
Author(s):  
R. E. Klinck ◽  
J. B. Stothers
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Aliphatic Aldehydes ◽  
Magnetic Resonance Studies ◽  
Unsaturated Aldehydes ◽  
Potential Use ◽  
Nuclear Magnetic

The effects of structure on the shielding of formyl protons of aliphatic aldehydes have been examined. The survey included examples of acyclic, alicyclic, and α, β-unsaturated aldehydes. The potential use of these results as an aid for structural elucidations is discussed, and the limitations are noted.

Sign in / Sign up

Export Citation Format

Share Document