Separation and Identification of Fatty Acids

An improved method is described for separating saturated fatty acids by reversed-phase paper chromatography. The 2,4-dinitrophenylhydrazides prepared from saturated fatty acids from C₂ to C₂₂ are run upward on paper impregnated with tetralin, using 90% methanol—acetic acid—tetralin, 80% ethanol—acetic acid—tetralin, or 90% methanol—tetralin as the moving solvent. The simultaneous separations of all even-carbon acids from C₆ to C₂₂, all odd-carbon acids from C₇ to C₁₉, and also all odd- and even-carbon acids from C₇ to C₁₉ can be successfully performed by means of this paper chromatography. The method is useful for the detection of component saturated fatty acids in natural fats.