水道水における残留塩素測定試薬の評価

抄録

One method of testing tap water for residual chlorine uses a diethyl-p-phenylenediamine (DPD) reagent. The test is very simple, consisting of adding DPD to the water to be tested and measuring residual chlorine from changes in the absorption of light (coloration). A false positive reaction, however, is known to proceed under the influence of ultraviolet light, making the coloration more intense. Care must therefore be taken with regard to sunlight when the method is used outdoors. In the present study, parameter design was used to develop a chlorine test reagent with high light tolerance. The test system as considered as a measuring instrument with residual chlorine concentration as input, variation pressure distance of optical absorption as output, and the presence or absence of irradiation by ultraviolet light as an error factor. An effective test wavelength was also found through selection analysis.