title: Comparison of various sampling schemes and accumulation profiles in covariance spectroscopy with exponentially decaying 2D signals.
abstract: Two-dimensional covariance (COV2D) spectroscopy offers an alternative approach to 2D Fourier transformation (FT2D) to obtain homo-nuclear correlation NMR spectra. Considerable saving in experimental time, without loss of resolution, can be achieved by incorporating COV2D with: (i) uniform sampling with a t1 cut-off (CUO) or non-uniform sampling (NUS), and (ii) constant or Gaussian accumulation profiles. We find that covariance treatment, combined with the CUO sampling and Gaussian accumulation profile provides better gain in experimental time, with respect to that required with FT2D NMR. This is in contrast with the maximum entropy (MaxEnt) reconstruction for 2D spectra, which works better with the NUS scheme rather than with the CUO scheme. We further discuss the experimental conditions that define this optimum acquisition, and explain how these parameters can easily be optimized 'on the fly' according to the desired resolution, which is quite sample-dependent.
authors: Physics Department & Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China.
authors: Yixuan
authors: Y
authors: Li
authors: Bingwen
authors: B
authors: Hu
authors: Qun
authors: Q
authors: Chen
authors: Qiang
authors: Q
authors: Wang
authors: Zhengfeng
authors: Z
authors: Zhang
authors: Jun
authors: J
authors: Yang
authors: Isao
authors: I
authors: Noda
authors: Julien
authors: J
authors: Trébosc
authors: Oliver
authors: O
authors: Lafon
authors: Jean-Paul
authors: JP
authors: Amoureux
authors: Feng
authors: F
authors: Deng