Abstract: The principle,application and setting of main parameters on EDIT technique suitable for FT-80A. NMR spectrometers are introduced in this paper.
When a set of APT parameters is used, the empirical values for the key parameter, LT, are as follows:
1 When set LT to 6, 7 or 8ms, the normal APT ¹³C spectra can be obtained.
2 When set LT to 4ms, the signal of all methyl carboons will vanish
3 when set LT to 2.9 or 3ms,tte intensity of quaternary carbons,compared. with those of the corresponding normal APT ¹³C spectra, can be greatly enhanced.
This rule can be generally applied in the identification of ¹³C-H groups of all organic compounds (C≡C of alkyne derivatives have not been tested)

Key words: coupling, modulation, pulse sequence, phase opposite, single spin-echo