Quantitative Analysis of Mixtures of Various Linear Anhydrides and Carboxylic Acids

Only a few quantitative methods have been described to analyze mixtures of symmetric anhydrides, mixed anhydrides and their corresponding carboxylic acids. Reversed-phase liquid chromatography using acetonitrile-water as solvent was optimized for the quantitative determination of such mixtures obtained by reacting acetic or propionic anhydrides with various fatty acids (from C3 to C18). Complex mixtures containing up to three mixed anhydrides, four symmetric anhydrides and four carboxylic acids have been quantitatively analyzed successfully in a single run.