水质监测中影响总氮空白吸光度的因素研究

Study on Factors Affecting Blank Absorbance of Total Nitrogen in Water Quality Monitoring

采用《水质 总氮的测定 碱性过硫酸钾消解紫外分光光度法》(HJ 636—2012)对地表水中的总氮进行检测时,空白试验吸光度常大于0.030,数值偏高,影响检测的准确性。空白试验吸光度的影响因素有试验用水、试剂纯度、试验器皿、样品消解与后处理、实验室环境等。本文通过科学试验,探讨了地表水水质监测中影响总氮空白吸光度的因素,找到最佳条件控制其空白吸光度,以期为水质总氮检测提供参考。

When using the "Determination of Total Nitrogen in Water Quality by Alkaline Potassium Persulfate Digestion Ultraviolet Spectrophotometry" (HJ 636—2012) to detect total nitrogen in surface water,the absorbance of blank test is often greater than 0.030,which is on the high side,affecting the accuracy of detection.The factors influencing the absorbance of blank test include test water,reagent purity,test vessels,sample digestion and post-treatment,laboratory environment,etc.Through scientific experiments,this paper discusses the factors that affect the blank absorbance of total nitrogen in surface water quality monitoring,and finds the best conditions to control the blank absorbance,so as to provide reference for total nitrogen detection of water quality.