5 results about "J-coupling" patented technology

This invention belongs to the field of nuclear magnetic resonance (NMR) detection technology, specifically relating to a method for detecting phosphorus-containing natural products in fermentation broth. The detection method includes: performing two-dimensional NMR spectroscopy on the fermentation broth to be tested, setting the J-coupling parameter to 20-30 Hz and 500-600 Hz respectively; when the J-coupling parameter is 20-30 Hz, the obtained... 1 H- 31 The signal in the p-NMR spectrum indicates a carbon-phosphorus natural product. 1 H- 31 P signal; when the J coupling parameter is 500~600Hz, the obtained 1 H- 31 The signal in the p-NMR spectrum indicates a hydrogen-phosphorus natural product. 1 H- 31 P signal; based on the obtained 1 H- 31 The p-NMR spectrum is used to determine whether the phosphorus-containing natural products in the fermentation broth are carbon-phosphorus or hydrogen-phosphorus natural products. This invention can directly detect carbon-phosphorus natural products in complex fermentation broths, providing a convenient method for rapid detection and identification of carbon-phosphorus natural products.

The invention discloses a multi-core J coupling constant-based pH measurement method, which comprises the following steps of: 1, preparing a series of compound samples with different pH values, and measuring J coupling constants of compounds in the samples; 2, drawing a coupling constant and pH relation curve of the compound J, and deducing a pH calculation formula; and 3, measuring the J coupling constant of the compound-containing sample to be measured, and determining the pH value of the sample to be measured. According to the method, the J coupling constant is measured through a nuclear magnetic resonance spectrum method or a zero field-near zero field J coupling spectrum method, and the pH value of the surrounding environment of the compound can be measured.

The invention discloses a phosphorus-hydrogen J coupling constant-based water content measurement method, which comprises the following steps of: 1, preparing a series of compound solutions with different water contents, and measuring J coupling constants of compounds in the solutions; 2, drawing a relation curve of a compound J coupling constant and the water content, and fitting a standard curvilinear equation; and 3, measuring the J coupling constant of the compound-containing solution to be measured, and calculating the water content of the sample to be measured. According to the method, the J coupling constant is measured through a nuclear magnetic resonance spectrum method or a zero field-near zero field J coupling spectrum method, and accurate quantitative measurement of the water content can be achieved.

The invention provides a high-field and near-zero-field combined magnetic resonance system, which comprises a sample tube for placing a sample, a high-field measurement module for pre-polarization of the sample and high-field chemical shift spectrum measurement, and a near-zero-field magnetic resonance module for J coupling signal measurement of the sample in the near-zero field, the sample transmission module is used for driving a sample to move between a high field and a near-zero field and maintaining nuclear spin polarization of the sample in the moving process; the digital control and signal processing module is used for automatic control and synchronous signal acquisition of the high field measurement module and the near-zero field magnetic resonance module; the invention also provides a high field and near zero field combined magnetic resonance detection method and a measurement method. According to the invention, a high-field spectrogram and a near-zero-field spectrogram are obtained in one measurement cycle, and unified correspondence of chemical shift and J coupling is realized. Through combination of high-field pre-polarization and rapid shuttling, the signal-to-noise ratio of near-zero field measurement is improved by about one order of magnitude, and the spectral line width is significantly reduced.