Absorptivity order and separation efficiency for high-molecular-weight alkylphenols under conditions of microchromatographic analysis

Abstract

1. It has been found that, as a result of liquid microchromatographic separation of octylphenol fractions on ASK silica gel, the products adsorbed include not only a concentrate of 2,6-, 2,4-di-, and 2,4,6-trisubstituted octylphenols, but also a group of octyl phenyl ethers. In gas-liquid chromatographic separation on the nonpolar liquid phase SE-30, the group of octyl phenyl ethers leaves the column ahead of the group of o-monooctylphenols. 2. In proportion to the yield from the silica-gel bed, in the groups of 2,6-, 2,4-di-, and 2,4,6-trisubstituted octylphenols, there is a redistribution of components: with a reduction in the content of 2,6-disubstituted and 2,4,6-trisubstituted octylphenols, the content of 2,4-disubstituted octylphenols increases, each of the groups increasing in the content of higher-boiling components, i.e., those having longer retention times on the nonpolar liquid phase SE-30. This can be explained (by analogy with the groups of o-and p-monoalkylsubstituted phenols) on the basis that there is an increase in adsorptivity on the silica gel when there is a change in the site of attachment of the benzene ring to the alkyl radical (from the center of the chain to the end).