应用相敏HMQC和HSQC谱准确测定异核碳-氢偶合常数

Phase sensitive HMQC(Heteronuclear Multiple Quantum Coherence) and HSQC(Heteronuclear Single Quantum Coherence) experiments with t 1 noise reduction are proposed for the accurate measurement of heteronuclear one bond 13 C 1H coupling constants. The resulting 2D spectra give anti phase splittings of heteronuclear one bond couplings along ω 2 dimension, so that the precision of coupling constant measurement is less subject to the residual t 1 noise. By combining use of data fitting procedure on a spectrum with enough digital resolution and signal to noise ratio, a precision of about 0 03 Hz can be achieved in the measurement of heteronuclear one bond coupling constants. The proposed method can be very useful for the study of residual dipolar couplings caused by the alignment in high magnetic field and the dynamic frequency shift caused by the cross correlation between chemical shift and spin dipolar interactions.

复杂基质中有机磷酸酯化合物的2D NMR快速分析

以有机磷酸酯为目标物,编译包含^(1)H-^(31)P异核多键相关谱(HMBC)和^(1)H-^(1)H DQF-同核位移相关谱(COSY)的NOAH2_BD脉冲序列,并与非均匀采样技术相结合,通过优化远程耦合演化延迟时间和非均匀采样比例等采集参数,得到^(1)H-^(31)P HMBC和^(1)H-^(1)H DQF-COSY谱图,实现了复杂有机废液中有机磷酸酯的快速鉴定。方法检出限可达到10μg/mL;与传统的二维核磁方法相比,在保持相近的谱图质量下,NOAH2_BD能将检测时间缩短44%, NOAH2_BD结合NUS=30%可将检测时间缩短82%。