5.2.1.3. MeOH—[OH−]-catalyzed transesterification.
For alkali-catalyzed transmethylation, NaOCH3,NaOH, and KOH can be used. Transmethylation with KOH–MeOH is used for triglycerides [301]. Alkaline esterification is preferred to acid methanolysis when the sample contains cyclopropane fatty acids, because alkali will not attack the cyclopropane ring [302]. Alkali metall methoxides in anhydrous methanol were used to catalyze transesterification [303]. Berdeaux et al., in a comparative study of several methylation methods, found the best recovery of short-chained FAs was obtained with base-catalyzed transesterification [276].