title: Esterification of fatty acids at room temperature by chloroform-methanolic HCl-cupric acetate.
abstract: A new procedure for the preparation of methyl esters from free fatty acids under mild conditions was investigated. Free fatty acids are dissolved in a mixture of chloroform-methanolic HCl-cupric acetate and kept at room temperature for 30 min for complete esterification. The method is suitable for esterification of long-chain acids, such as 18:0, and for very long chain acids, such as 24:0. Fatty acids from brain glycerophosphatides, which included a high concentration of polyenes such as 20:4 (n - 6), 22:4 (n - 6), and 22:6 (n - 3), were also esterified by the same procedure, and neither artifact formation nor loss of unsaturated acids was observed.
mesh_terms: D002247:Carbon Isotopes; D002725:Chloroform; D002849:Chromatography, Gas; D003300:Copper; D004952:Esters / Q000138:chemical synthesis; D005227:Fatty Acids; D006851:Hydrochloric Acid; D013058:Mass Spectrometry; D000432:Methanol; D008722:Methods; D013229:Stearic Acids; D013696:Temperature; D013997:Time Factors
chemical_list: D002247:Carbon Isotopes; D004952:Esters; D005227:Fatty Acids; D013229:Stearic Acids; D003300:Copper; D002725:Chloroform; D006851:Hydrochloric Acid; D000432:Methanol