Matrix effect on the retention in reversed-phase liquid chromatography

Summary A polymer-based, reversed-phase column (VA-C18), prepared by grafting octadecyl chain onto vinyl alcohol copolymer gel, was investigated for its chromatographic characteristics. n-Alkanes and n-alkyl alcohols were found to be retained only by hydrophobic interaction between the solutes and the octadecyl chain. In the case of aromatic hydrocarbons, in addition to the hydrophobic interaction, - interaction between the solutes and the based material was elucidated to contribute to the retention. For aromatic tertiary amines which are known to strongly interact with the residual silanol group of the silica-based reversed-phase columns to produce broadened and skewed peakes, the VA-C18 column also retained these substrates strongly by the combination of hydrophobic, -, and ionic interactions. In this case, however, symmetrical peaks were observed. From these results, it was determined that in the case of VA-C18, the base material was found not to produce undesirable effect although the solutes interact with the base. Further conclusion obtained was that in reversed phase liquid chromatography, chromatographic properties of base matrix is highly responsible for the overall retention.