总氮测定中空白吸光值的控制方法

分析了总氮测定过程中影响空白值的一些因素及控制方法。总氮测定过程中,消解温度和时间、蒸馏水纯度、试剂选用和存放时间、器皿洁净度等等均会影响到试验空白吸光值。笔者提出采用消解温度控制在120～124℃、消解时间在45 min、空白样消解后加入蒸馏水、选用分析纯试剂、试剂存放时间小于7 d等措施可以有效地控制试验空白吸光值。

Control Methods of Blank Absorbance Values in the Determination of Total Nitrogen

This article analyzes a number of factors affecting the blank values during the process of determination of total nitrogen and thier control methods.In the total nitrogen determination process,many factors will affect the test blank absorbance values,such as the digestion temperature and time,distilled water purity,reagent selection and storage time,cleanliness of utensils,etc.The author has proposed a few measures that can effectively control the experimental values of the blank absorbance,for instance the...