title: Quantification of hydroxylic groups in a river humic substance by (29)Si-NMR.
abstract: Quantification of the hydroxylic functions of carboxylic, phenolic and alcoholic groups in a selected river humic substance (Ruhr/Germany) is performed by methylation/silylation and (29)Si-NMR analysis. The well known methylation/silylation procedure of Thorn et al. is modified by carrying out the diazomethane methylation in the presence of the proton catalyst p-toluene sulphonic acid. Additional experiments by both (13)C-NMR-spectroscopy and potentiometric acid-base titration confirm the results obtained by (29)Si-NMR.
authors.affiliation: Institut für Spektrochemie und Angewandte Spektroskopie, Postfach 10 13 52, D-44013, Dortmund, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Herzog
authors.forename: P
authors.initials: P
authors.lastname: Burba
authors.forename: J
authors.initials: J
authors.lastname: Buddrus