Quantitative determination of cyclopropenoid fatty acids in cottonseed meal

A rapid analytical procedure for determining the residual cyclopropenoid fatty acids (CPA) in cottonseed meal has been developed. The procedure involves room-temperature extraction of crude CPA-containing lipids with a hexane-water-acetone azeotrope solvent, followed by a benzenemethanol wash. The crude lipids are then converted to methyl esters by methanolysis with sodium methoxide. Extraction with petroleum ether, followed by washing with aqueous acetone, results in a substance which is free from interfering materials. The purified methyl esters are then analyzed for CPA by a spectrophotometric modification of the Halphen reaction.