影响总氮空白测定因素的实验探讨

Experimental Investigation on Factors Affecting Determination of Total Nitrogen Blank

水质中总氮的测定采用碱性过硫酸钾消解紫外分光光度法(HJ 636-2012),对本方法中影响总氮测定的各种因素进行了实验探索和结果分析。在实验探索中,主要是从实验用水、实验试剂、实验器皿(主要是比色管)等方面研究总氮测定过程中对空白的影响。实验结果分析表明:实验用水只要是新鲜制备的去离子水,分别通过两台纯水机的水都能满足空白值要求。过硫酸钾和氢氧化钠的纯度、碱性过硫酸钾溶液和1+9盐酸溶液的存放时间、比色管的洁净程度等均会影响总氮的空白值。结合综上所述方案,可以得到最优化的总氮空白值为0.010的吸光度。

This paper use alkaline potassium persulfate digestion - UV spectrophotometry （ HJ 636 -2012） to determine the total nitrogen in water. It analyze the influencing factors that will affect the determination of total nitrogen in the experiment. In the experiment exploration, mainly affecting the course of study on the determination of total nitrogen from the blank experiment with water, laboratory reagents, labware （mainly colorimetric tube） and so on. The experimental results showed that：experiments with water as long as freshly prepared deionized water, respectively, through the water, two water machine can meet the require- ments of the blank value. Purity potassium persulfate and sodium hydroxide, an alkaline solution of potassium persulfate and stor- age time of 1 ＋ 9 hydrochloric acid solution than cleanliness etc will affect the color tube blank value of total nitrogen. Combined sum scheme, you can get the optimum value of the absorbance of 0. 010 TN blank.