replaced by a shaped pulse. In the following description we refer to instruments with transmitter attenuation. You have to set:

two different transmitter attenuation levels
td	8 k
sw	2.5 ppm
o1	on resonance of a chosen multiplet line of the sample
p1	180° ¹H transmitter pulse at chosen attenuation, here 0.8 s at 90 dB was used, see Exp. 2.9
p2	30° ¹H transmitter pulse with normal attenuation (3 dB), be sure not to use a 90° pulse
d1	5 s
ns	1

Record a normal ¹H NMR spectrum of the sample. Load a pulse program for the SPT experiment and adjust the power of p1 to γB₁ = 1 Hz, typically in the order of 90 dB attenuation (see Exp. 2.9). Adjust o1 to the left-most signal of the sample, record its SPT spectrum and repeat the experiment for all signals of the AMX spin system.

5. Processing

Use standard 1D processing as described in Experiment 3.1

6. Result

In the figure the normal ¹H NMR spectrum taken on an AMX-500 spectrometer is shown in a. In b line X₄ was irradiated and in c line X₃. Note that in b lines A₂ and M₃ are attenuated, whereas A₁ and M₁ are enhanced. In c lines M₄ and A₁ are attenuated, M₂ and A₂ are enhanced.

AMX energy-level and transition scheme for the homonuclear SPT experiment