| 摘要 |
PROBLEM TO BE SOLVED: To eliminate interference influence caused by an alkali metal ion or the like, and to immerse an electrode directly into a sample without pretreatment such as masking so as to measure ammonium ion easily. SOLUTION: This device is provided with a cylindrical sensor body 2 storing a reference electrode internal solution 3, a reference electrode internal electrode 4 and a pH measuring glass electrode in its inside, a diaphragm 10 provided in a condition abutting on a response film 7 of the glass electrode 5 in an end part opening side of the sensor body 2 to permeate ammonium gas, and an ion permeable thin film 11 provided in a sample side of the diaphragm 10, and containing a reagent having strong alkali buffering ability to substitute ammonium ion in a sample with ammonia gas. Interference influence by alkali metal ion or the like is eliminated thereby, and the electrodes are directly immersed into river water, lake water, swamp water, in particular sea water containing a large amount of sodium, and the like without pretreatment such as masking, so as to measure easily ammonium ion. |
