Retention behaviour of carbohydrate oligomers in reversed-phase chromatography

The retetnio behaviour of starch and cellulose hydrolysates on alkyl-modified silica columns using aqueous eluents has been studied. The influence of eluent pH, addition of sodium chloride or alcohols to the eluent, pore diameter of the silica support and chain length of the alkyl modification were investigated. It was concluded that a neutral aqueous eluent is a better eluent than one of low or high pH; the addition of sodium chloride results in an increased retention time and better resolution; the addition of very small amounts of pentanol-1 (<0.1%, v/v) is a useful means of decreasing of the retention times. Silica supports with a larger pore diameter than the commonly used 60–100 Å and alkyl modifiers between octyl and octadecyl are also useful for decreasing the retention times.