总氮测定中消解损失的原因分析及解决方法  

Analysis of Loss in Digesting Loss in Measuring Total Nitrogen and Solution

作　　者：蒋文洁 潘虹[2] 

机构地区：[1]上海城投污水处理有限公司水质检测中心,上海200083 [2]上海市环境监测中心,上海200030

出　　处：《环境科学与管理》2010年第4期143-144,共2页Environmental Science and Management

摘　　要：总氮是衡量水质的重要指标之一。它是无机氮和有机氮的总和,按理说总氮的值应大于氨氮、亚硝酸盐氮、硝酸盐氮之和,但实际检测工作中有时会出现总氮的测定结果小于这三氮的总和。为此通过对不同浓度的氨氮样品进行总氮的测定,并根据消解过程的化学方程式分析产生该问题的原因,从而得到:用碱性过硫酸钾消解总氮过程中,氨氮会以氨气形式挥发损失,导致总氮测定值偏低,而且氨氮的含量越高,总氮在消解过程中的损失越多。此外,在此基础上,对总氮测定过程中各因素进行改进探讨,通过对比实验最终得出:在取样时确保测定结果在标准曲线范围内的前提下,使氨氮的含量在40μg以下再消解测定总氮,是较好的解决总氮测定中消解损失的方法。Total nitrogen is one of the important indicators of water quality.It is the sum of inorganic and organic nitrogen.According to reason general,total nitrogen value should be greater than the sum of ammonia,nitrite,nitrate nitrogen.But the actual check sometimes occur as a result of the determination of total nitrogen is less than the sum of these three nitrogen.So through determination of total nitrogen of different concentrations of ammonia-nitrogen samples and the analysis of the cause of the problem according to the chemical equation of the process of digestion,resulting in that ammonia-nitrogen loses in the form of ammonia with base potassium peroxodisulfate digesting total nitrogen and result of total nitrogen will be lower.The higher ammonia-nitrogen content,the higher the total nitrogen in losses during digestion.In addition,on this basis,discussing every element influencing digestion.By contrast,it shows that adjusting the sampling volume to make result in the range of calibration curve and measuring total nitrogen with the content of ammonia-nitrogen below 40 μg is the best way to solve loss in digesting total nitrogen.

关 键 词：总氮三氮 消解损失 解决方法 

分 类 号：X830.2[环境科学与工程—环境工程]