过硫酸钾法测定总氮空白值的影响因素分析
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摘要
对水质总氮测定中影响空白值吸光度的因素进行探讨,通过实验确定了提高总氮测定准确度的条件。实验结果表明:可用超纯水代替无氨水;国产过硫酸钾需重结晶1～2次可满足纯度要求;碱性过硫酸钾溶液最好即用即配,储存时间不得超过7d;试样置于压力锅升温至120℃开始计时30min,降压取出自然冷却60min后进行后续操作,完全可满足空白值吸光度小于0.030要求。
The factors affecting the absorbance of blank values in the determination of total nitrogen in water were discussed, and the conditions for improving the accuracy of total nitrogen determination were determined through experiments. The experimental results show that: ultra-pure water can be used instead of ammonia-free water; domestic potassium persulfate needs to be recrystallized 1 or 2 times to meet the purity requirements; alkaline potassium persulfate solution is best used immediately, storage time should not exceed 7 d; After the pressure cooker is heated to 120 °C, the time is 30 minutes, and the pressure is taken out and naturally cooled for 60 minutes, and then the subsequent operation is performed, which can completely satisfy the requirement that the blank value absorbance is less than 0.030.
The factors affecting the absorbance of blank values in the determination of total nitrogen in water were discussed, and the conditions for improving the accuracy of total nitrogen determination were determined through experiments. The experimental results show that: ultra-pure water can be used instead of ammonia-free water; domestic potassium persulfate needs to be recrystallized 1 or 2 times to meet the purity requirements; alkaline potassium persulfate solution is best used immediately, storage time should not exceed 7 d; After the pressure cooker is heated to 120 °C, the time is 30 minutes, and the pressure is taken out and naturally cooled for 60 minutes, and then the subsequent operation is performed, which can completely satisfy the requirement that the blank value absorbance is less than 0.030.
引文
[1]李坤.总氮测定中空白吸光度值偏高问题的实验探讨[J].环境科学导刊,2017,36(5):84-86.
[2] HJ 636—2012水质总氮的测定碱性过硫酸钾消解紫外分光光度法[S].北京:中国环境科学出版社,2012.
[3]钟金鸣,张智超.HJ636-2012在测定TN空白值相关问题分析[J].水利科技与经济,2017,23(6):6-9.
[4]张念,刘祖文,郭云,等.浸矿废水中总氮测量的影响因素及相关对策[J].工业水处理,2016,36(5):102-105.
[5]汪曼,李津津,张晓淳.碱性过硫酸钾法测定总氮中试剂的选择[J].广州化工,2015,43(15):165-166.
[6]陈伟宏,黄爱荣,苏飞.测定工业废水总氮分析方法的探讨[J].资源和环境,2016,42(12):119-120.
[7]黄玲,章方扬.总氮测定中空白值的影响因素及其控制方法[J].中国无机分析化学,2013(3):79-82.
[8]孙启彬.碱性过硫酸钾法测定总氮中影响因素及解决方法[J].环境科学与管理,2012,37(8):132-134.
[2] HJ 636—2012水质总氮的测定碱性过硫酸钾消解紫外分光光度法[S].北京:中国环境科学出版社,2012.
[3]钟金鸣,张智超.HJ636-2012在测定TN空白值相关问题分析[J].水利科技与经济,2017,23(6):6-9.
[4]张念,刘祖文,郭云,等.浸矿废水中总氮测量的影响因素及相关对策[J].工业水处理,2016,36(5):102-105.
[5]汪曼,李津津,张晓淳.碱性过硫酸钾法测定总氮中试剂的选择[J].广州化工,2015,43(15):165-166.
[6]陈伟宏,黄爱荣,苏飞.测定工业废水总氮分析方法的探讨[J].资源和环境,2016,42(12):119-120.
[7]黄玲,章方扬.总氮测定中空白值的影响因素及其控制方法[J].中国无机分析化学,2013(3):79-82.
[8]孙启彬.碱性过硫酸钾法测定总氮中影响因素及解决方法[J].环境科学与管理,2012,37(8):132-134.