Molecular sizes of solutes in tetrahydroturan were re-examined with some new test compounds; in general, they gave the expected molecular size based on additive structural elements determining the effective size. The effective size of phenols was consistently larger than one might predict, and phenols typically appeared to be 4.67 carbon atoms larger than the corresponding aromatic hydrocarbon. A range of 2,2,4-trimethyldioxolane derivatives were studied, and they gave the expected sizes. The gases studied eluted at a molecular size slightly smaller than propane. Some implications of this observation are given. General uses and advantages of the method are listed and some predictions as to future developments are given. A chromatogram of 13 solutes in GPC is included to show the efficiency of the separation. © 1968, American Chemical Society. All rights reserved.
