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.

Abstract: An electrode is composed of a membrane, provided with open pores running through said membrane, the walls of the pores having an electrically conducting polymer coating, containing a redox enzyme bound thereto. In these type of electrodes a direct electron transfer is possible between the redox enzyme, e.g. glucose oxidase, and the electrically conducting polymer, e.g. polypyrrole. Such an electrode, which can be produced in a simple manner, has extensive application possibilities such as, for example, in a biosensor or in a production installation for the preparation of specific chemicals. As starting materials for the electrodes of the invention, use can be made of marketed porous membrane materials as well as of latex particles. The walls of the pores of porous membrane and the interstices of the latex particles respectively are provided with a thin layer of the electrically conducting polymer which in turn is provided with a redox enzyme suitable for the pursued aim.