紫外法测定水质中总氮的影响因素研究

Research on the Influence Factors of Total Nitrogen Determination in Water Quality by UV Spectrophotometric Method

结合紫外法测定水质中总氮空白校正吸光度值易偏高、测定结果准确度低的问题,分别从检测试剂含氮量、选择实验用水、清洗玻璃器皿、改进实验操作、改进消解环境等多个方面分析了各影响因素对总氮测定的影响,相应提出了采用测定含氮量的方法筛选试剂、新制备的去离子水作为总氮实验用水、每次总氮实验使用新刷好的器皿、增加颠倒混匀步骤提高测定结果的准确度和精密度、高压蒸汽灭菌器应定时清洗换水等对策与建议。

In view of the problems existed in total nitrogen determination in water quality that the absorbance value of blank correction is on the high side, and the accuracy of determination results is low, the article analyzed the influencing factors＇s impact on total nitrogen determination respec- tively from detecting reagent nitrogen compounds, selecting experimental water, cleaning glassware, improving experimental operation, improving digestion environment, and put forward some sugges- tions, such as screening reagent by determining nitrogen compounds, using fresh deionized water as experimental water, using new brushed glassware, adding the step of putting upside down and blending to improve the accuracy and precision, cleaning high pressure steam sterilizer and chang- ing water timing accordingly.