Characteristics of C4- and C8-bonded vinyl alcohol copolymer gels for reversed-phase high-performance liquid chromatography

Abstract The fundamental characteristics of C 4 - and C 8 -bonded polymer (C4P and C8P) gels developed for reversed-phase high-performance liquid chromatography and obtained by introduction of butyryl and octanoyl groups, respectively, at the hydroxyl groups of vinyl alcohol copolymers were investigated and compared with the characteristics of a previously developed C 18 -bonded polymer (ODP) gel obtained in a similarf manner and with those of commercial C 4 -, C 8 - and C 18 -bonded silica gels. For both alkyl alcohols and standard proteins, the retention strength on the polymer gels clearly increased with increasing number of carbons in the bonded alkyl group and thus in the order C4P, C8P, ODP. The C4P and C8P gels, like the ODP gel and in clear contrast to the silica gels, displayed excellent tolerance toward acidic, alkaline and buffered eluents. They also exhibited minimal shrinking and swelling effects with variations in eluent polarity, as measured by their solvent regain.