影响工作场所空气中氨的测定因素

Factors Affecting the Determination of Ammonia in the Air of Workplace

本文对影响氨测定结果的因素进行了总结分析,如实验用水的影响、大型气泡吸收管洗涤和保存的影响、吸收液的配置过程的影响、关键化学试剂和显色温度的影响、整个比色过程时间的控制影响等。结果显示,二级超纯水完全可以替代蒸馏水;吸收管最好专管专用,避免交叉污染;吸收液应现配现用;温度为20~25℃时,显色反应完全;显色剂纳氏试剂应轻拿轻放,取上清液,使用完毕需放2~5℃冰箱避光保存;尽量把比色过程的时间控制在40 min左右,能达到较为理想的试验结果。

This paper summarizes the factors that may affect the results of ammonia determination,such as the influence of test water,the washing and preservation of large bubble absorption tubes,the influence of the configuration process of absorption solution,the influence of key chemical reagents and color rendering temperature,and the control of the whole colorimetric process time,so on.The results show that the secondary ultrapure water could completely replace distilled water,the absorption tube should be specially designed to avoid cross-contamination,the absorption solution should be ready for use,the color reaction is complete when the temperature is 20—25℃,the color reagent Nessler's reagent should be handled lightly,the supernatant should be taken out and stored in a refrigerator at 2—5℃ after use,when the reaction is complete,the time of colorimetric process can be controlled at about 40 minutes,which can reach the ideal test results.