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

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