真空检测管-电子比色法快速测定水中的化学需氧量

Rapid determination of Chemical Oxygen Demand in water by vacuum detection tube-electron colorimetry

真空检测管—电子比色法属于测定水中CODCr快速分析方法,结果表明,方法对30～2500mg/L浓度范围的相对误差为-3. 3%～-15. 6%,3个浓度标准样品相对标准偏差为3. 9%～7. 7%,其准确度和精密度均能够满足标准方法(HJ659-2013)质控要求。使用实际水样稀释相近浓度的标准样品,测定回收率在92. 4%～103%之间。在与实验室重铬酸盐法监测结果对比来看,废水相对误差较小,地表水样品由于水样浓度较低,相对误差略大。真空检测管—电子比色法属于快速分析方法,小巧便捷,操作方便,大大缩短了分析时间,有较好的准确稳定性,适合现场条件复杂、样品量大、分析频率高、要求及时性强的地表水巡查、污染源普查、应急监测等方面。

Vacuum detection tube-electron colorimetry is a rapid analysis method for the determination of COD Cr in water.The results show that the relative error of the method is-3.3%-15.6%for the concentration range of 30-2500 mg/L.The relative standard deviation of the three concentration standard samples is 3.9%-7.7%,its accuracy and precision can meet the quality control requirements of the standard method(HJ659-2013).Standard samples with similar concentrations were diluted with actual water samples,and the recovery was determined to be between 92.4%and 103%.Compared with the monitoring results of laboratory dichromate method,the relative error of wastewater by the vacuum detection tube-electron colorimetry is smaller;however the surface water sample has a slightly bigger relative error due to the low concentration of water sample.Vacuum detection tube-electronic colorimetry is a fast analysis method,which is small and convenient,easy to operate,greatly shortens the analysis time,has better accuracy and stability,is suitable for surface water inspection,pollution source survey,emergency monitoring and other fields which have complex field conditions,large sample size,high analysis frequency,and strong timeliness.