Method for chromatographic analysis

Abstract

In chromatographic analysis by the steps of adding a sample solution to a flow of an eluant, passing the eluant flow through a separation column thereby converting the eluant flow into an eluate flow containing component ions of the eluant flow in separate zones, passing the eluate flow through an ion-exchange membrane tube thereby allowing the eluate to come into contact with an aqueous solution of an H.sup.+ form or OH.sup.- form electrolyte outside the tube through the wall of the membrane tube, substituting those of the component ions contained in the eluate flow which have the same type of electric charge as H.sup.+ or OH.sup.- with said H.sup.+ or OH.sup.- thereby giving rise to a deionized solution flow, and passing the deionized solution flow through a detection cell thereby causing the component ions which have survived the substitution to be detected as separated into distinct zones, improvements are obtained by causing the aqueous solution of H.sup.+ or OH.sup.- form electrolyte to be contacted with an insoluble ion exchanger of the same H.sup.+ or OH.sup.- type as said electrolyte to the aqueous solution. Use of a high molecular weight electrolyte having a molecular weight of 500 or more permits detecting anion or cation present in a very low concentration with ample sensitivity and high reproducibility without provision of forwarding means.