The application of PE
film-based measurements can further simplify and facilitate
low-cost FTIR TFA analyses. from local markets. All of the reagents, chemicals, and solvents,
such as anhydrous ether, methanol, hexane, and potassium
hydroxide (KOH), were of analytical grade. The pure standards of
FAMEs and trielaidin (>99%) were obtained from Sigma–Aldrich
(Sigma–Aldrich Trading Co., Ltd., Shanghai, China)