title: Implementation of real-time two-dimensional nuclear magnetic resonance spectroscopy for on-flow high-performance liquid chromatography.
abstract: Directly coupled HPLC-NMR has become a powerful tool for separation and structural elucidation of unknown compounds. However, there are only a few reports on application of on-flow two-dimensional (2D) NMR in HPLC-NMR. Here we present an alternative method for recording real-time 2D-NMR spectrum (total correlation spectroscopy, TOCSY) on a commercial HPLC-NMR system. The method is based on well-established Hadamard matrix for 2D-NMR frequency encoding. In addition, a modified/improved solvent suppression approach is incorporated. This makes it possible to carry out the experiment with both polar and gradient eluents, the widely used chromatographic conditions. The method is example using a synthesized mixture of three amino acids (His, Phe and Try) and a human urine sample. The method demonstrated here may be utilized for high-throughput structural or unknown component identification and fast dynamic study in a variety of applications.
authors.affiliation: State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Zhou
authors.forename: Wenxian
authors.initials: W
authors.lastname: Lan
authors.forename: Weinong
authors.initials: W
authors.lastname: Zhang
authors.forename: Xu
authors.initials: X
authors.lastname: Zhang
authors.forename: Sheng'an
authors.initials: S
authors.lastname: Xia
authors.forename: Hang
authors.initials: H
authors.lastname: Zhu
authors.forename: Chaohui
authors.initials: C
authors.lastname: Ye
authors.forename: Maili
authors.initials: M
authors.lastname: Liu
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006626:Hippurates / Q000652:urine; D006639:Histidine / Q000302:isolation & purification*; D006801:Humans; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D010649:Phenylalanine / Q000302:isolation & purification*; D012984:Software; D014364:Tryptophan / Q000302:isolation & purification*
chemical_list: D006626:Hippurates; D010649:Phenylalanine; D006639:Histidine; D014364:Tryptophan; C030514:hippuric acid