摘要
在１２０℃～１２４℃的碱性介质条件下，用过硫酸钾作氧化剂，将水样中氨（铵）、亚硝酸盐以及有机氮化合物转化为硝酸盐，并且在此过程中大部分有机物也同时被氧化分解。用紫外分光光度法分别于２２０ｎｍ、２７５ｎｍ波长处测定其吸光度。用校正的吸光度 Ａ＝Ａ(２２０)－２Ａ(２７５)及氮的含量绘制校准曲线，从而计算水样中总氮含量。该方法具有良好的精密度和准确度、操作简便、消除干扰能力强、检测下限低等优点。方法的线性范围为 ０.０５ｍｇ／ｌ－４ｍｇ／ｌ，水样加标回收率为９６.５％- ９０.０％，相对标准偏差在２.１％以内，检测下限为０.０５ｍｇ／ｌ。
Ammonia、nitrite and organic nitrogenous compound are oxidized to nitrate by the oxidant potassium persulfate in alkaline medium at temperature of 120℃-124℃. Most of organic compound are oxidized at the same time. Determinate the absorptivity of nitrate at wavelength of 220nm and 275nm by UV spectrophotometric method. Draw calibration curve by absorpivity A=A_(220)-2A_(275)and the content of nitrogen. This method has many advantages, such as high precision and accurary、convenient operation good interfere elimination and detectability. In addition, by using this method the linear range was 0. 05mg/l-4mg/l, the recovery was 96. 5 % -- 99. 0 %, the relative standard deviation was less than 2. 1 % and the detdction limit was 0. 05mg/l.
出处
《现代科学仪器》
1999年第5期64-65,共2页
Modern Scientific Instruments
关键词
过硫酸钾消解
紫外分光光度法
总氮
废水
测定
Alkaline potassium persulfate digestion UV spectrophotometric method Total nitrogen
