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Online Coupling of Size‐Exclusion Chromatography and Low‐Field 1 H NMR Spectroscopy
Author(s) -
Cudaj Markus,
Guthausen Gisela,
Hofe Thorsten,
Wilhelm Manfred
Publication year - 2012
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.201200290
Subject(s) - chemistry , analytical chemistry (journal) , nuclear magnetic resonance spectroscopy , solvent , size exclusion chromatography , spectrometer , protonation , resolution (logic) , polymer , nuclear magnetic resonance , chromatography , organic chemistry , ion , physics , quantum mechanics , artificial intelligence , computer science , enzyme
Current results and limitations of a novel SEC–MR–NMR (size‐exclusion chromatography–medium resolution nuclear magnetic resonance) system are presented, delivering a direct correlation of chemical structure and molecular weight. A 20 MHz 1 H NMR spectrometer based on permanent magnets was combined with a SEC setup. The NMR sensitivity was improved by digital filters, shims, and a self‐built flow probe when compared with time‐domain instruments. For optimum NMR signal‐to‐noise ratio ( S / N ) of polymer fractions and concomitantly reduced S / N of solvent signals, deuterated solvents or protonated solvents, with solvent suppression, were applied. Results are presented after optimization of both NMR and chromatographic components such as column dimension and volume flow.