对测定总氮新标准(HJ636—2012)的探讨

Discussion on New Standard Method HJ 636- 2012 for Determining Total Nitrogen

碱性过硫酸钾消解紫外光度法是测定总氮的常用方法。对《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)进行了探讨和改进,结论如下:采用标准曲线代替工作曲线不影响测定;减少消解液的用量,准确控制消解液的加入量,可以使空白值降低并且保持稳定,满足大部分实际样品的测定。通过碱性过硫酸钾溶液的配制、贮存方式、比色管的清洗方式等试验,对新标准部分内容进行了探讨。

Alkaline potassium persulfate digestion ultraviolet speetrophotometry is a commonly used method for determining total nitrogen. Water Quality - Determination of Total Nitrogen - Alkaline Potassium Persulfate Digestion UV Spectrophotometric Method （ HJ 636 - 2012 ） was discussed and improved. The conclusions were as follows： the adoption of the standard curve instead of working curve did not affect the test results ; and the reduction of digestion solution and the accurate control of the amount of digestion solution could lead to the reduction and stability of the blank value, satisfying the measurement of most of the actual samples. Through alkaline potassium persulfate solution preparation, storage and cleaning colorimetric tube test, part of the new standard was discussed.