title: Quantitative 2D HSQC (Q-HSQC) via suppression of J-dependence of polarization transfer in NMR spectroscopy: application to wood lignin.
abstract: A quantitative method to record (1)H-(13)C correlation NMR spectra (Q-HSQC) is presented. The suppression of (1)J(CH)-dependence is achieved by modulating the polarization transfer delays of HSQC. In addition, the effect of homonuclear couplings, as well as relaxation during the pulse sequence are discussed. We developed the Q-HSQC approach for the quantitative analysis of wood lignin, a complex polymer where it has been difficult to obtain reliable data on the relative amounts of different structural units. The current method is applicable to a variety of complex mixtures, where normal 1D (1)H- and (13)C-NMR methods fail.
authors.affiliation: NMR laboratory, Structural Biology and Biophysics, Institute of Biotechnology, P.O. Box 65, FIN-00014 University of Helsinki, Finland.
authors.forename: Sami
authors.initials: S
authors.lastname: Heikkinen
authors.forename: Merja M
authors.initials: MM
authors.lastname: Toikka
authors.forename: Pirkko T
authors.initials: PT
authors.lastname: Karhunen
authors.forename: Ilkka A
authors.initials: IA
authors.lastname: Kilpeläinen
mesh_terms: D008031:Lignin / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D014934:Wood
chemical_list: D008031:Lignin