The Error Range Of DOSY Experiment And Its Influencing Factors In NMR

Diffusion-ordered spectroscopy(DOSY)is an important method for measuring the self-diffusion coefficient D of sample in solution.According to the literature,the self-diffusion coefficient of the sample under different conditions can usually be measured,and the issues such as molecular binding and intermolecular interaction are discussed through the change of the self-diffusion coefficient with the DOSY experiment.However,it is doubtful in some cases whether the results of the DOSY experiment can accurately reflect these subtle changes.In response to this situation,this thesis conducts a systematic study of the error range and influencing factors of the DOSY experiment: The main contents are as follows:1.From the point of view of experiment,the influencing factors of the error are investigated from two aspects: experimental conditions and acquisition parameters.The experimental conditions mainly include two factors: temperature control and airflow,and two factors easily introduce convection effects experimental results.The acquisition parameters mainly include indirect dimension sampling data points,total number of scans and number of dummy scans.2.From the point of view of data processing,explored the factors that have the greatest impact on the results of the two processing methods.In the processing of the DOSY spectrum,the digital resolution has a greater influence;in the exponential fitting,it mainly explores the number of data points affects its result.3.The systematic error of DOSY experiment is fully studied.Under the premise of controlling many influencing factors,the systematic error of the experiment is obtained,and the standard of the error comparison is grasped.In summary,this thesis systematically studies the error of DOSY experiment from two aspects of experiment and processing,and discusses its influencing factors,providing a more reliable basis for the DOSY experiment.