Transesterification of fatty acid ethoxylates in supercritical methanol, then gas chromatography-mass spectrometric determination of the derived methyl esters, for identification of the initiators.
Unknown fatty acid ethoxylate samples have been transesterified in supercritical methanol, using a loop made of a stainless-steel tubing as the reactor vessel. The initiator acids, now present as the corresponding methyl esters, were determined by gas chromatography-mass spectrometry (GC-MS). Quantitative transesterification is achieved by heating a solution of the ethoxylate sample in methanol at 280 degrees C for 10 min under pressure. The influence of reaction time, temperature, and presence of a Lewis acid catalyst has been investigated. The method of transesterification was optimized in respect of low cost, short reaction time, and availability to laboratories with standard analytical equipment.
Socher
G
G
CarboGen Laboratories (Neuland) AG, Hunzenschwil, Switzerland. gunthersocher@carbogen.com
Nussbaum
R
R
Rissler
K
K
Lankmayr
E
E
D001880:Boranes / Q000737:chemistry; D004951:Esterification; D005227:Fatty Acids / Q000032:analysis* / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D013329:Structure-Activity Relationship; D013501:Surface-Active Agents / Q000032:analysis* / Q000737:chemistry; D013696:Temperature
D001880:Boranes; D005227:Fatty Acids; D013501:Surface-Active Agents; C021274:boron trifluoride