微波加热快速测定环境水样中的CODMn

利用微波加热技术,在密闭容器内压力消解,用高锰酸钾法快速测定了西流湖水、黄河水等环境水样和标准水样(CW82,中国环境监测总站)中的COD_(Mn),并与经典方法进行了对照测定,结果令人满意。本法十几分钟内可消解十几个样品,Cl_-离子含量高达1000mg/L时亦不产生干扰,COD_(Mn)的检测下限为0.26mg/L,上限为15.0mg/L,室内测定的RSD<4％,多次加标回收率在97.0～105.6％之间,标准水样测定结果的相对误差为0.3％。适用于轻度污染水体COD_(Mn)的批量分析。

Rapid Determination of CODMn in Environ-mental Water Samples Using Microwave-Heating Digestion Method

A new microwave-heating digestion method was developed for the rapid determination of COD of water samples taken from Xiliu lake, Yellow river as well as a standard water sample (CW82: Environmental Monitoring Station of China). Water samples were dispelled in a closed-vessel with potassium permanganate under the action of microwave and as many as 14 samples could be treated each time. High Cl- content (up to 1000 mg/L) did not interfere with the determination. The detection range of COD was found between 0.26 mg/L and 15.0mg/L, relative standard deviation less than 4.0%(n = 5 or 6), recovery ranging from 97.0% to 105.6%, and relative error 0.3% for the determination of CW82 standard water sample. Compared to the classical method, this method proved to be simple, rapid, accurate and suitable for the determination of CODMn of lightly polluted water.