Application of a silica gel column for the simultaneous determination of alkali and alkaline-earth metal ions with indirect photometric detection using benzyltrimethylammonium chloride as visualization agent

Ion chromatography system for the simultaneous determination of inorganic monovalent and divalent cations was developed using a 50 × 4.6 mm i.d. separation column packed with porous silica gel. The separation was carried out using a mobile phase consisting of benzyltrimethylammonium chloride in aqueous acetonitrile. Alkali and alkaline-earth metal ions were separated within 15 min and indirectly detected at 220 nm. The present method was applied to the determination of monovalent and divalent cations present in river water and urine samples.