Method and device for analyzing ionic components in ultrapure water

A method for analyzing ionic components in ultrapure water, in which sample ultrapure water is concentrated and analyzed by an analysis part, the method comprising:

• concentrating the sample ultrapure water by an electrodialyzer,
• in which the electrodialyzer is a second electrodialyzer that comprises a first anion exchange membrane, a dialysis membrane, and a second anion exchange membrane arranged in this order between an anode and a cathode, and that comprises an anode chamber, a first generation chamber, a second generation chamber, and a cathode chamber arranged in this order from the anode to the cathode, wherein the method comprises:
• passing sample ultrapure water through the first generation chamber;
• passing a nitric acid aqueous solution through the anode chamber and the cathode chamber;
• passing a high-purity nitric acid aqueous solution through the second generation chamber, the high-purity nitric acid aqueous solution being generated by transmitting NO3− ions through an anion exchange membrane by a dialysis treatment and causing the NO3− ions to move in ultrapure water;
• and
• analyzing concentrated water from the second generation chamber by the analysis part.