Non-suppressed ion chromatography of cations on silica gel modified with aluminium

The presence of aluminium in the silica matrix causes an enhancement of the acidity of the silanol group on silica gel. Therefore, in order to prepare silica-based cation-exchangers for ion chromatography (IC) under strongly acidic eluent conditions, modification of silica gel with aluminium using a coating method was carried out. As a result, aluminium-adsorbing silica gels were found to act as a cation-exchangers under strongly acidic eluent conditions and were successfully applied to the conductimetric detection IC for the separation of common mono- and divalent cations using nitric acid-2,6-pyridinedicarboxylic acid eluent. These results strongly indicate that the modification is a simple and effective way for the preparation of advanced silica-based cation-exchangers for IC.