DPD分光光度法测定循环水中余氯的改进

Improving and Suggestions for Determining Residual Chlorine in Cycle Water with DPD Photometry

针对以N,N-二乙基对苯二胺分光光度法测定循环水中余氯时出现的问题进行了实验研究。结果表明,不同的氯标准溶液、显色剂与水样的加入顺序和显色时间对测定的结果均有干扰。建议采用与水中有效氯存在状态接近的氯标准溶液来绘制标准曲线;采用先加入显色剂后再加入水样的方法来避免次氯酸的漂白作用对测定的干扰。

This paper studied the problems on determining residual chlorine in cycle water with DPD photometry. The results showed that the standard solution of chlorine, sequence of color-developing agent and water sample and coloration time had influences on the test results. Suggestions were put forward that the standard curve should be produced by using standard solution of chlorine, which is close to the state of chlorine in water, and the blanching influence of hypochlorous acid on determination could be avoided by adding color-developing agent before adding water sample.