偶氮光度法测定废水苯胺类化合物存在问题及解决方案

Problems and Solutions for Determination of Aniline in Waste Water with Azo Spectrophotometry

蒸馏法、脱色法是GB/T 11889—1989和《水和废水监测分析方法》（第4版增补版）推荐的N-（1-萘基）乙二胺偶氮分光光度法测定苯胺类常用的前处理方法。研究结果表明,蒸馏法回收率低,不适用于测定含高沸点苯胺类化合物的废水,因此对脱色法进行了改进。25 m L水样定量加入3 g脱色剂,脱色后用滤膜过滤;脱色剂的使用导致测定结果偏低,应同步制作工作曲线。工作曲线在0.25~4 mg/L范围内线性关系良好,相关系数为0.999 7,检出限为0.03 mg/L,有证标准物质测定结果均在不确定度范围内,实际样品加标回收率92.0%~107%,相对标准偏差2.0%~3.6%,方法的检出限、准确度、精密度均能满足检测要求。

Distillation,decolorization are common pre-treatment methods for determination of aniline with N-（ 1-naphthyl） ethylenediamine spectrophotometry by GB / T 11889—1989 and 《water and wastewater monitoring analysis method》（ fourth edition）recommend. The results show,distillation recovery rate is low,does not apply to the determination of waste water containing high boiling compounds of aniline. The decoloration method was improved. Join the 3g bleaching agent in 25 m L solutions,after decoloration by membrane filtration; working curve should be made synchronously,otherwise the result is low,a good linearity was in range from 0. 25 ~ 4 mg / L（ r = 0. 999 7）,the detection limit of 0. 03 mg / L,results of certified reference materials are measured in the range of uncertainty,spiked recoveries of samples are between 92. 0% ~ 107%,the relative standard deviations are between2. 0% ~ 3. 6%,the detection limits,accuracy,precision can meet the testing requirements. Chroma compensation act applies to shallower water,spiked recoveries of samples are between 93. 8% ~ 103%,the relative standard deviation of actual samples are between 3. 0% ~ 3. 2%.