The invention relates to a dialysis cell for sample preparation for a chemical analysis method, in particular for ion chromatography. The dialysis cell comprises a donor channel and an acceptor channel extending parallel thereto. The donor channel and the acceptor channel are separated from each other by a selectively permeable dialysis membrane. In particular, an analyte that is dissolved in a donor solution in the donor channel can enter through the dialysis membrane into the acceptor solution in the acceptor channel. The acceptor channel has at least in some sections a volume that is smaller than the volume of the donor channel extending parallel thereto. Acceptor and donor channels are formed from half-cells, between which the dialysis membrane is arranged, wherein the donor channel and the acceptor channel are designed in each case as a recess in a contact surface of one of the half-cells with the dialysis membrane.