用TPPI方法消除2D COSY和MQSY实验中与辐射阻尼有关的谐波峰(英文)

ELIMINATION OF RADIATION DAMPING RELATED ARTIFACTS IN 2D COSY AND MQSY NMR SPECTRA USING TPPI TECHNIQUE

在二维相关（ＣＯＳＹ）和多量子（ＭＱＳＹ）实验中，ＴＰＰＩ（Ｔｉｍｅ－ｐｒｏｐｏｒｔｉｏｎａｌ－ｐｈａｓｅ－ｉｎ－ｃｒｅｍｅｎｔ）方法被用于消除与辐射阻尼相关的谐波峰．二维实验中，π／２混合脉冲常常非线性地改变磁化强度的进动相位．这一非线性变化和辐射阻尼一起导致依赖于化学位移偏置的谐波．然而，如果混合脉冲的相位正比于演化时间ｔ１，谐波消失，但水峰保持不变．

Time proportional phase increment (TPPI) techique is used to remove the radiation damping related harmonic peaks from two dimensional correlation (COSY) and multiple quantum (MQSY) spectra. In 2D experiments, the mixing π/2 pulse usually changes the phase of the water magnetization nonlinearly. The combination of this nonlinear phase change with radiation damping results in chemical shift offset dependent harmonic peaks. However, if the phase of the mixing pulse is proportional to the evolution time t 1, the harmonic peaks disappear completely while the water peak remains unchanged.