MEASURING METHOD OF CHEMICAL OXYGEN DEMAND

PROBLEM TO BE SOLVED: To provide a COD measuring method for accelerating an oxidation reaction by irradiating ultraviolet ray, even without a catalyst. SOLUTION: This method using a COD measuring device is equipped with a photooxidation device equipped with only a carrier liquid sending tube, wherein a carrier solution flows in order to send a sample solution, an oxidizer liquid sending tube for sending an oxidizer solution containing an oxidizer for oxidizing the sample solution; a junction between the carrier liquid sending tube and the oxidizer liquid sending tube; an ultraviolet lamp for irradiating ultraviolet rays; and a second capillary connected to the first capillary. With an absorption detector for detecting the quantity of the oxidizer after reaction, the sample solution sent from the inside of the carrier liquid sending tube and the oxidizer solution sent from the inside of the oxidizer liquid sending tube are mixed together in the junction, to thereby prepare a mixed solution comprising only the carrier solution, the sample solution and the oxidizer solution, and the ultraviolet rays irradiated from the ultraviolet lamp are irradiated to the mixed solution; and the sample solution is reacted with the oxidizer in the oxidizer solution, and then the quantity of the oxidizer in the mixed solution is detected. COPYRIGHT: (C)2009,JPO&INPIT