总氮空白值影响因素及水样保存条件影响浅析

Analysis on the influence factors of total nitrogen blank value and water sample preservation conditions

用碱性过硫酸钾消解紫外分光光度法测定总氮,简单易操作,但空白值易受外部条件影响而偏高。探讨了试剂纯度、消解剂添加量、实验用水质量、冷却放置时间、消解时间和消解剂保存时间等条件对空白值的影响。同时,分析了不同保存条件对水样总氮值的影响。

The determination of total nitrogen by ultraviolet spectrophotometry with alkaline potassium persulfate digestion is simple and easy to operate,but the blank value is easy to be affected by external conditions and high.The effects of reagent purity,amount of digestion agent,quality of experimental water,cooling time,digestion time and storage time of digestion agent on blank value were discussed.At the same time,the effect of different preservation conditions on the total nitrogen value of water samples was analyzed.