光电比色法测量化学需氧量的优化研究

Optimization of Measurement of Chemical Oxygen Demand by Photoelectric Colorimetry

文章进行了光电比色法测量化学需氧量的优化研究,结果表明样品在155℃下只需消解15 min,冷却到室温后及时测量,其结果的相对标准偏差较小,而且冷却方式对测量值影响不大。再分别用重铬酸盐法、光电比色法测定国家环境标准样品与环境样品的化学需氧量,经t检验法与F检验法验证,两方法并没有显著性差异,但光电比色法更具有较高的准确度和精密度。本实验中经优化的消解条件不仅可以使样品消解时间缩短,消解试剂用量少,直接得出结果,而且测量结果准确度和精密度好,可快速、准确、批量测定水环境样品中化学需氧量。

The digestion condition of measurement of chemical oxygen demand by photoelectric colorimetry was optimized. The relative standard deviation was smaller that samples were fully cooled to room temperature after digested at 15 min under 155℃. Cooling method didn＇t affect the result. The environmental certified standards and environmental samples were respectively measured by reflux method and optimized photoelectric colorimetry and analyzed by t-test and F-test. No significant difference was found. There was higher accuracy and precision in measuring chemical oxygen demand by photoelectric colorimetry. The digestion time was shortened and consumption of digestion reagent was reduced. The accuracy and precision of the results were excellent, which could be obtained directly. And this was a quick and precise method, which water environmental samples could be batch determined.