Abstract: Apparatus for eliminating halide ions such as chloride ions from aqueous solutions having a hollow cylindrical sample holding chamber (2), the front end of which has an orifice (3) and in the vicinity of which is disposed a filter plate (4) that extends over the cross section of the sample holding chamber (2) and is liquid-permeable and essentially impermeable for solids and is inserted in a fixed manner into the hollow cylinder; a plunger (6) which can move to and fro in the sample holding chamber (2) and has a plunger stem (7) attached thereto engages in the open rear end (5) of the sample holding chamber, and, in the sample holding chamber (2) between the filter plate (4) and the plunger (6) is disposed a freely movable bed (7) of an adsorbent reacting with halide ions and forming a sparingly soluble compound, which bed fills a part of the sample holding chamber (2). The adsorbent is preferably charged with silver nitrate as compound reactive with halide ions.