ORSAT and modifications of SEFT and APT

Up to now, three subspectra are usually needed for the complete assignment of all signals in C-13 spectrum: two DEFT spectra (phi = 90 degrees and phi = 135 degrees) and a proton decoupled spectrum. In this paper, we present a method in which a complete assignment becomes possible with merely two sp ectra. For this purpose, a new pulse sequence (ORSAT) has been elaborated b y using off-resonance irradiation. The method described here is a further d evelopment of SEFT and APT. The second required spectrum is a DEFT (phi = 1 35 degrees). Signal assignment of cholesteryl acetate is demonstrated as an example. C-13 routine spectroscopy can be significantly accelerated by app lying this method, (C) 1999 Academic Press.