水中臭氧的快速测定

建立了水中臭氧的ＫＩ－硫酸－４－氨基－Ｎ，Ｎ－二乙基苯胺（ＤＰＤ）分光光度测定法。此方法是在ｐＨ３．５条例上，根据臭氧与碘化钾的定量反应：Ｏ３＋２Ｉ＾－＋２Ｈ＾＋→Ｏ２＋Ｉ２＋Ｈ２Ｏ，生成的Ｉ２与ＤＰＤＰ反应显粉红色，在５１０ｎｍ处用分光光度计测定，直接测定的线型范围为０～１．００ｍｇ／Ｌ，最低检测浓度为０．０１ｍｇ／Ｌ，相对标准偏差为１．２％～２．７％（ｎ＝１０），回收率在９８．６％～１０６．６

Rapid determination of the ozone in water

A new potassium iodide--N, N-diethy1-1,4-phenylen-ediammonium sulfate (DPD) spectrophotometry method for the determination of the ozone in water was established. The method was based on the quantitative reaction between the ozone and potassium iodide in buffered solution(pH 3.35): O3 + 2I- + 2H+-->O2 + I2 + H2O. Iodine could react with DPD regent and produce pink color. Its absorption was determined at 510 nm with spectrophotometer. The range of direct determination was 0-1.00 mg/L. Beer's law was obeyed in this range. The detection limit was 0.01 mg/L. The relative standard deviations were from 1.2% to 2.7% (n = 10). The recoveries were from 98.6% to 106.6%. Water samples were determined with both this method and iodimetry. The results were comparable. The method was applied to the determination of the ozone in water sample with satisfactory results. It was practical and reliable.