Maximum entropy signal processing in practical NMR spectroscopy

摘要: NMR spectroscopy is intrinsically insensitive, a frequently serious limitation especially in biochemical applications where sample size limited and compounds may be too insoluble or unstable for data to accumulated over long periods. Fourier transform (FT) was developed by Ernst1 speed up the accumulation of useful data, dramatically improving quality spectra obtained given observing time recording free induction decay (FID) directly time, at cost requiring numerical processing. Ernst also proposed that more information could from spectrum if FID multiplied suitable apodizing function before being transformed. For example (see ref. 2), an increase sensitivity can result use matched filter1, whereas resolution achieved gaussian multiplication1,3, application sine bells4–8 convolution difference9. These methods are now used routinely The maximum entropy method (MEM)10 theoretically capable achieving simultaneous enhancement both respects11, this has been borne out practice other fields it applied. However, technique requires relatively heavy computation. We describe here first practical MEM NMR, we analyse 13C 1H 2-vinyl pyridine. Compared with conventional spectra, gives considerable suppression noise, accompanied significant enhancement. Multiplets resolved better leading improved visual clarity.