to make FAMEs from FAs we use BF3 in methanol, see some of my publications

Dear Naira

Acid catalyzed trans-esterification is the most common method in the preparation of fatty acid methyl esters (FAMEs). In general methonolic complex of Boron trifluoride (BF3) is used as a catalyst as it is a Lewis acid. A sulfuric acid-methanol method is used with success to derivatize very long chain fatty acids (C24:0-C36:0) (Mendez Antolin E et al., J Pharm Biomed Anal 2008, 46, 194). Notwithstanding, acidic conditions generated by 3M HCl in dry methanol or methanolic sulfuric acid have been also described.

Base catalyzed trans-esterification in general, is not preferred choice since free fatty acids are not subject to nucleophilic attack by alcohols or bases and thus are not esterified in these conditions. However, the brief methodology is as follows.

Up to 10 mg of lipids are dissolved in 2 ml hexane followed by the addition of 0.2 ml of 2 M methanolic KOH. The tube is vortexed for 2 min at room temperature. After a light centrifugation, an aliquot of the hexane layer is collected for GC analysis. It must be pointed out that sterol esters and waxes do not react under these conditions.

A modification and an adaptation of that procedure has been proposed allowing the direct preparation of fatty acid methyl esters from polar lipids (phospholipids) in lipid mixtures without prior isolation (Ichihara K et al., Lipids 2010, 45, 367). No obvious differences were found between the fatty acid compositions of phospholipids determined by that method and those determined by conventional methods, including lipid extraction with chloroform/methanol followed by isolation of polar lipids by chromatography.

An alternative base-catalyzed methodology in mild conditions was adapted for milk or seed lipids using K tert-butoxide and 2-methoxyethanol (Destaillats F et al., Lipids 2002, 37, 527).

Thank you very much for your valuable suggestions.

We supply a kit called Shinwa DS-TG that is more rapid and efficient.