REAGENT FOR MEASUREMENT OF RESIDUAL CHLORINE

摘要

The purpose of the present invention is to provide a powdery reagent for measuring residual chlorine, which comprises both a DPD dye and a buffering agent, rarely absorbs moisture when the reagent contacts with external air upon the opening of a container of the regent for carrying out the operation of the measurement of effective chlorine, is not adhered to a measurement section of a measurement vessel due to the absorption of moisture or does not undergo the consolidation or alteration of properties in the vessel during being stored after the opening of the container or being accommodated in the measurement vessel for use, and has low moisture absorbency. The present invention provides a reagent for measuring residual chlorine, which comprises: (A) a diethyl-p-phenylenediamine sulfuric acid salt; (B) a buffering agent which has a solid form in ambient temperature, is still stable after being mixed with the diethyl-p-phenylenediamine sulfuric acid salt, has a powdery form that is not consolidated even after being exposed for five minutes under a temperature of 30°C and a humidity of 50%, has a saturated solubility of 1 g or more in 100 g of water having a temperature of 20°C, and can be prepared into a 1% aqueous solution having a pH value of 5.5-7; and (C) an excipient.