Impact of remote protonation on 13C CPMAS NMR quantitation of charred and uncharred wood

Simple item page
dc.contributor.authorSmernik, R.
dc.contributor.authorBaldock, J.
dc.contributor.authorOades, J.
dc.date.issued2002
dc.descriptionCopyright © 2002 Elsevier Science (USA). All rights reserved.
dc.description.abstractThe impact of inefficient cross polarization (long TCH values), caused by long 13C-1H internuclear distances, on 13C CPMAS NMR spectra of charred and uncharred woods is determined by simultaneously fitting data from complementary variable spin lock and variable contact time experiments. As expected, the impact is minimal for uncharred woods, but is very significant for the charred woods. Quantification of the decrease in CPMAS signal intensity caused by both inefficient cross polarization and rapid T1rhoH relaxation is achieved using an advanced spin counting methodology, for which the term "spin accounting" is proposed. 13C CPMAS NMR observabilities determined using the spin accounting methodology were close to 100% for the uncharred samples, and 69-82% for the charred samples. This represents a large improvement on the 30-40% observabilities determined using other spin counting techniques. Furthermore, it is shown that remote protonation and rapid T1rhoH relaxation are roughly equally responsible for the low signal intensity of standard (I ms contact time) 13C CPMAS spectra of charcoal.
dc.description.statementofresponsibilityRonald J. Smernik, Jeffrey A. Baldock and J. Malcolm Oades
dc.description.urihttp://www.elsevier.com/wps/find/journaldescription.cws_home/622947/description#description
dc.identifier.citationSolid State Nuclear Magnetic Resonance, 2002; 22(1):71-82
dc.identifier.doi10.1006/snmr.2002.0065
dc.identifier.issn0926-2040
dc.identifier.issn1527-3326
dc.identifier.orcidSmernik, R. [0000-0001-6033-5855]
dc.identifier.urihttp://hdl.handle.net/2440/27296
dc.language.isoen
dc.publisherElsevier Science BV
dc.source.urihttps://doi.org/10.1006/snmr.2002.0065
dc.subjectProtons
dc.subjectCharcoal
dc.subjectCarbon Isotopes
dc.subjectMagnetic Resonance Spectroscopy
dc.subjectModels, Statistical
dc.subjectSensitivity and Specificity
dc.subjectReproducibility of Results
dc.subjectMolecular Structure
dc.subjectRotation
dc.subjectWood
dc.titleImpact of remote protonation on 13C CPMAS NMR quantitation of charred and uncharred wood
dc.typeJournal article
pubs.publication-statusPublished

Files

Collections

Soil and Land Systems publications