| 摘要 |
PURPOSE:To provide a hardness determining chemical agent which consists of an aqueous soln. contg. 1-(1-hydroxy-4-methyl-2-phenol azo)-2-naphthol-4-sulfonic acid, triethanolamine and a pH controller, and which makes hardness decision of water easy and sure and permits the same rapidly. CONSTITUTION:5-50wt% Triethanolamine as a chemical agent for effecting pH control, obliterating against disturbing ions and viscosity control of compounded soln. and for stabilizing the coloring for the purpose of determination for a long period of time as well as 0.05-2.0wt% an acid which is colorless in water and does not make insoluble salts with hardness components or its salt as a pH controller are compounded in an aqueous soln. contg. 0.01wt% 1-(1-hydroxy-4-methyl-2-phenol azo)-2-naphthol-4-sulfonic acid whereby the aqueous soln. of 9.1-11.4pH is prepd. Further, if 0.1-10wt% sodium sulfide is compounded to the above-described aqueous soln., high obliterating power is obtained despite the presence of copper and zinc as disturbing ions in the water to be determined. |
