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Separation of resin acids using cyclodextrin‐modified capillary electrophoresis
Author(s) -
Luong John H. T.,
Rigby Tracey,
Male Keith B.,
Bouvrette Pierre
Publication year - 1999
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/(sici)1522-2683(19990601)20:7<1546::aid-elps1546>3.0.co;2-b
Subject(s) - chemistry , chromatography , micellar electrokinetic chromatography , acetonitrile , resin acid , capillary electrophoresis , abietic acid , cyclodextrin , hydrolysis , methanol , organic chemistry , rosin
A cyclodextrin‐modified capillary electrophoretic method has been developed for the analysis of eleven common resin acids using a pH 4.5, 20 m M sodium acetate buffer containing 10% acetonitrile, 20 m M methyl‐β‐cyclodextrin (MECD) and 30 m M sulfobutylether‐β‐cyclodextrin (SBCD) as buffer modifiers. At pH below their p K a (< 5.7—6.4) the resin acids were virtually unionized and insoluble; however, they formed water‐soluble inclusion complexes with MECD (20 m M ) or SBCD (30 m M ) even at pH 4.5. The analytes were separated in 25 min and, with the exception of two pairs, 12‐ or 14‐chlorodehydroabietic/12,14‐dichlorodehydroabietic acid and dehydroabietic/palustric acid, the remaining resin acids were baseline‐separated. Analysis time was significantly shortened (< 12 min) at pH 9.25 using 30 m M SBCD and 20 m M MECD in 20 m M sodium borate. Resin acids were baseline‐separated with the exception of two pairs, pimaric/ sandaracopimaric acid and 12‐ or 14‐chlorodehydroabietic/abietic acid. The addition of 7.5% methanol to the running buffer resolved the abietic acid peak. Both HPLC and micellar capillary electrokinetic chromatography using 20 m M deoxycholic acid, 10% acetonitrile in 20 m M sodium borate, pH 9.25, failed to resolve the resin acids. The simple capillary electrophoretic method developed would be useful for the rapid separation and characterization of several important resin acids in pulp mill effluents and other contaminated samples.