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Separation of fatty alcohol ethoxylates by capillary zone electrophoresis and micellar electrokinetic chromatography
Author(s) -
Koike Ryo,
Kitagawa Fumihiko,
Otsuka Koji
Publication year - 2009
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.200800553
Subject(s) - micellar electrokinetic chromatography , fatty alcohol , chromatography , capillary electrophoresis , chemistry , alcohol , electrokinetic phenomena , capillary electrochromatography , capillary action , organic chemistry , materials science , composite material
Separation methods based on capillary zone electrophoresis and micellar electrokinetic chromatography were developed to characterize the distribution of ethylene oxide (EO) homologues in the fatty alcohol ethoxylates (FAEs). Prior to the separation, the FAEs were derivatized with 2‐fluoro‐1‐methylpyridinium p ‐toluenesulfonate (FMPTS) to allow CZE separation and UV detection. To prevent adsorption of cationic analytes onto the inner surface of the capillary and formation of micelles in CZE analysis, a lower pH background solution (BGS) containing a high concentration of acetonitrile was employed. Under optimal conditions, FMPTS‐derivatized FAEs with an average EO number of 6 were completely separated within 11 min. For MEKC analysis of the FAEs, dodecyltrimethylammonium chloride (DTAC) was added to the BGS. In the presence of 30 mM DTAC in 10 mM phosphate buffer (pH 2.5) containing 20% (v/v) acetonitrile, superior oligomer separation of the FAEs containing up to 50 EO groups was achieved within 30 min with good analytical reproducibilities. Furthermore, the developed method was applied to the analysis of the FAEs in commercial products such as laundry detergent and fabric softener.