Abstract: An apparatus for the pre-concentration of a sample substance for spectroscopical reasons in the flow injection analysis having an ion-exchanger column of conical shape filled with a granular ion-exchanger. For pre-concentration of the sample, the sample liquid flows through the ion-exchanger column from the smaller first end. Then the pre-concentrated elements are eluted by an eluting liquid from the wider second end. Therewith, a very low dispersion of the eluted sample slug results. Thus, a considerable increase in the degree of sensitivity can be achieved with high analysis frequency.