A method for the analysis and separation of macromolecules is proposed, based on the effect of the chromatographic "invisibility" of some chain fragments, namely blocks of a certain type in block copolymers, grafted chains in graft copolymers and linear elements of macromolecules with rings. When certain critical conditions for such fragments of polymer molecules are created neither the length nor the molecules weight distribution of these molecules influences the retention volume, and this effect is treated as a chromatographic "invisibility" of the elements involved.
Results of the modern theory of chromatography and the direct simulation of the equilibrium behaviour of macromolecules in a chromatographic column have been taken into account and conclusion is drawn that this method of "invisibles" provides an efficient separation of macrocycles and linear polymers and the separation of macromolecules according to the number of functional groups. The method of "invisibles" also makes it possible to separate two-block copolymers according to the size of the "visible" block only, and to separate grafted polymers according to the backbone length. The scope of the application of the method to chromatographic analyses of copolymers is discussed.