Abstract
Separation behavior of inorganic anions and organic acids is discussed by non-suppressed ion chromatography with a short column (5 cm×0.46 cm I. D.) packed with a silica-based ion exchanger (TSKgel IC-Anion-SW), which is prepared by chemically bonding diethylaminomethyl group on the surface of hydrophilic packings with the trade name TSKgel G2000SW. This has a particle diameter of approximately (58)μm and an exchanger capacity of approximately 0.4 meq/g. Monovalent inorganic anions were completely separated with a 1 mM tartaric acid (pH 3.2) or 10mM potassium benzoate (pH 6.6) solution as eluent, and divalent inorganic anions with a 4mM potassium phthalate (pH6.5) or 1mM ammonium citrate (pH 6.5) solution as eluent. Aromatic-organic acids were easily eluted with a 0.5 mM ammonium citrate (pH 6.5) solution as eluent. The results obtained with conductometric determination were confirmed by comparison with direct or indirect UV absorbance and electrochemical detection. This approach will be applied to the rapid separation of hydrophobic ionic species and the mutual separation of hydrophilic ionic species.
