Displacement Separation of Some of the Component Fatty Acids of Milk Fat

Nine fatty acids of milk fat, from butyric to stearic, were separated by displacement chromatography.This method appears to be adaptable to the separation of volatile and nonvolatile fatty acids by first saponifying the fat and then acidifying the soaps on the column just prior to carrier displacement analysis.Editor.Displacement separation is a special technique of chromatographic separation, in which the column is developed by a solution of a substance which is more strongly adsorbed than the components of a sample.After the column is washed with solvent, the sample to be separated is pressed into the column.A solution of the displacer substance is then pressed onto the column and, because it is more strongly adsorbed than are the components of the sample, these are displaced and migrate down the column according to their relative adsorbabilities, the least adsorbed material migrating first.Each substance in the chromatogram thus displaces the component with the next lower adsorbability, and the components migrate in zones one after the other.The zones are detected and the concentrations of solute in the effluent may be measured interferometrically.Acids, so separated, may be titrated with alkali.Carrier displacement chromatography makes use of relatively large quantities of substances whose adsorption isotherms lie between those of the components of the sample.When the sample components and the added carrier substances are displaced, the constituents arrange themselves in order of adsorbability, and the components of the sample are sandwiched between much larger zones of the added substances.