EFFECT OF FUNCTIONAL-GROUPS ON THE RETENTION BEHAVIOR OF ANIONS IN ION CHROMATOGRAPHY USING A COATED SILICA COLUMN

The effect of functional groups on the retention behaviour o some anio ns was investigated in ion chromatography using ODS columns coated wit h several quaternary ammonium or phosphonium salts that have various f ree alkyl groups on the nitrogen and phosphorus atoms. The retention b ehaviour of strongly retained monovalent anions, such as nitrate and b romide, was greatly affected by the alkyl groups. However, those of di valent and weakly retained monovalent anions were little affected. The retention of anions on the quaternary phosphorus atom were stronger t han those on the quaternary nitrogen atom.