Abstract: Some metal ions are separated on a 10 urn bonded column coated with cetylpyridinium by using aminopolycarboxylic acid as the complex reagent.The retention of the metal complexes is due to ion-interaction between the anionic complexes and the sorbed cationic cetylpyridinium.Bi,Co, Pb, Mn, Ni and Cu ions can be completely separated with EDTAas the comoplex reagent,and the detection limits of the metal ions are 0.8, 2, 30, 100, 80 and 50 ng at 230 nm respectively.Co, Bi, Ni, Fe, Cu and Pb ions can be completely separated with DTPAas the complex reagent, and the detection limits of the metal ions are 80, 4, 400, 5, 20 and 100 ng at 254 nm respectively.

Key words: Ion-interaction chromatography, Metal ions, Cetylpyridinium, Aminopolycarboxylic acid complex reagent