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A New Method for the Analysis of the Substitution Pattern of Hydroxyethyl(methyl)‐Celluloses Along the Polysaccharide Chain
Author(s) -
Mischnick Petra,
Unterieser Inga,
Voiges Kristin,
Cuers Julia,
Rinken Marian,
Adden Roland
Publication year - 2013
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.201300070
Subject(s) - chemistry , reductive amination , substituent , hydrolysis , reagent , electrospray ionization , oligosaccharide , cationic polymerization , mass spectrometry , cellulose , chromatography , hydrazone , polymer chemistry , polymer , organic chemistry , catalysis
Abstract Hydroxyethylmethyl celluloses (MS HE 0.15–0.26, DS Me 1.49–1.82) and hydroxyethyl celluloses (MS HE 1.89–3.03) are analyzed with respect to their substituent distribution in the polymer chains. The cellulose ethers are peralkylated and partially hydrolyzed, and are analyzed by electrospray ionization‐ion trap‐mass spectrometry (ESI‐IT‐MS). The randomness of the partial hydrolysis is proven. Quantitative evaluation of their mass spectra becomes possible after labeling the oligosaccharides at the reducing end. Reductive amination with o ‐aminobenzoic acid gives better results than hydrazone formation with cationic Girard's T reagent. Syringe pump infusion gives more‐accurate results compared with liquid chromatography (LC)‐ESI‐MS. Profiles of the substituent distribution in the oligosaccharide fractions of DP 2–DP 7 are compared with the theoretical random distribution of glucosyl units in the chain.