The estimation of fatty acids of intermediate chain length by partition chromatography.

In 1942 Smith (1) demonstrated that the silica gel partition chromatogram, first developed by Martin and Synge (2), would separate a mixture of formic, acetic, propionic, n-butyric, and n-valeric acids in chloroform-l per cent butanol into its component acids. In 1945 Ramsey and Patterson (3) confirmed this work and presented a partition chromatographic method for the qualitative separation and identification of formic, acetic, propionic, and butyric acids. In 1946 Elsden (4) presented a method based on the work of Smith by which acetic, propionic, and n-butyric acids in biological materials can be quantitatively separated and estimated. Elsden’s method is limited in that the butanol-chloroform-water system he employs will not separate fatty acids having 5 or more carbon atoms. In an investigation of the rAle of fatty acids in Cheddar cheese flavor, the present authors found it necessary to develop a rapid method for the quantitative estimation of formic, acetic, propionic, n-butyric, caproic, caprylic, and capric acids. By use of t.he system benzene-aqueous sulfuric acid in partition chromatograms such a me%hod was devised and is presented here.