水样容器对亚硝酸盐测定的影响研究

Impact of Water Container on Determination of Nitrite Nitrogen and Its Solution

在实际工作中发现一些环境水样的亚硝酸盐测定结果存在虚高现象,并证实了这与采样及运输过程中容器材质选择不当及未按相关规定严格对新启用容器进行前处理有关。通过理论计算提出了通过其高锰酸盐指数值判断亚硝酸盐测定值合理性的方法,并通过实验证实了其可行性。选择几种常见的市售聚乙烯容器进行模拟实验,结合模拟实验结果和实际工作总结,发现选择合适的材质、并在新启用聚乙烯采样容器时按照相关标准进行恰当的处理,可以在检测时间范围内有效避免亚硝酸盐测定值虚高的情况发生。

The artificial high determinations of nitrite nitrogen was found in the actual work,and had been linked to the wrong selection of container material without strict pretreatment. The reasonable determination of nitrite nitrogen can be determined by its permanganate index（ CODMn） according to theoretical calculation,which had been confirmed in this article. To verify the viewpoint of this article,several different kinds of polyethylene products were chosen for experiment. Combining the experimental results with the actual work summary,it is conclude that the artificial high determinations of nitrite nitrogen outlined in the article could be avoided by a appropriate water container with correct purge at a time.