Development of direct size-exclusion chromatography separation for the determination of molar mass of native procyanidins in the phenolate form.

A size-exclusion chromatographic method using an aqueous solvent as eluent was developed for the determination of the molecular mass of procyanidins has been developed. Size-exclusion chromatography is a chromatographic technique used to determine molecular weight distribution of polymers. During the development work, PL aquagel-OH columns and several different eluent compositions were investigated. The best separation of procyanidins was obtained with an eluent consisting of water-methanol (50:50, v/v), NaNO3: 0.18 M, pH < pKa + 2. The results from this aqueous SEC method were compared with results obtained using SEC with organic solvents.