Time-proportional phase incrementation detection

Proton-proton homonuclear decoupling has been performed by the ESLG decoupling sequence [46]. Quadrature detection in coj was achieved by using the time proportional phase increment method (TPPI) [47]. During the acquisition period, two pulse phase modulation (TPPM) heteronuclear decouphng ]48] was applied (Figure 7.6). 

Time proportional phase incrementation and order selective detection using 3D NMR... 

The quadrature detection mode is given as a suffix to the main sequence name me magnitude calculated, TPPI time proportional phase increment, E/A Echo / Antiecho The term "selective" is reserved exclusively for sequences using selective pulses. If selectivity is achieved using other methods this is defined using a different term. 

Howevei on modern spectrometers, the COSY experiment is now carried out in phase-sensitive mode through the use of one of two modifications introduced to achieve quadrature detection in the ti axis, as well as in 2 which is done conventionally. These two approaches are called the States-Haberkorn method and time proportional phase incrementation readers are referred to the Fmrher Reading section for details. 

NMR experiments were carried out at 15 C on a Bruker AMX-500 spectrometer equipped with a 5 mm inverse detection probe and an X-32 computer. All ID spectra were recorded with a 5500 Hz spectral width and 8k data points. The water resonance was suppressed either by a pre-saturation irradiation or by using a tailored jump-return excitation pulse l. Phase-sensitive detection in the tl dimension of 2D experiments was achieved using the time-proportional phase incremental scheme. ... 

In 2D NMR, it is not possible to use a second detector in the fi dimension. There are alternatives which provide the equivalent of phase sensitive detection in the dimension two of these are the States method and time proportional phase incrementation (TPPI). 

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