Abstract: System for analyzing the concentration of a number of different ions in a watery solution, using a capillary zone electrophoresis apparatus comprising a capillary tube extending between an input opening and a detection area and filled with an electrolyte, an input device for injecting a sample of the solution to be analyzed in the input opening of the capillary tube, a voltage source for establishing a voltage gradient along the capillary tube between the input opening and the detection area to evoke a migration of the ions in the same through the capillary tube, and a detector circuit for detecting the ions passing through the capillary tube by measuring the conductivity of the passing fluid. The system comprises furthermore a processor for calculating the ion concentrations, the processor receiving data from the detector circuit and from a further conductivity sensor providing to the processor data representing the total conductivity of the solution from which the sample was taken.