石墨消解仪–凯氏定氮法测定土壤中全氮量  

Determination of total nitrogen in soil by graphite digester-Kjeldahl method

作　　者：刘宗超 蔡兴 文田耀[1] 赵春梅 孙文军[1] 朱静 LIU Zongchao;CAI Xing;WEN Tianyao;ZHAO Chunmei;SUN Wenjun;ZHU Jing(The First Institute of Geological and Mineral Resources Survey,Henan Province Geological Exploration Bureau,Luoyang 471000,China;School of Chemical Engineering and Food,Zhengzhou Institute of Engineering Technology,Zhengzhou 450044,China)

机构地区：[1]河南省地矿局第一地质矿产调查院,河南洛阳471000 [2]郑州工程技术学院化工食品学院,郑州450044

出　　处：《化学分析计量》2022年第12期55-58,共4页Chemical Analysis And Meterage

摘　　要：采用石墨消解仪–凯氏定氮法测定耕地土壤中全氮量,探讨了催化剂种类、浓硫酸使用量、消解时间对全氮含量测定的影响。当使用硫酸钾、硫酸铜和硒粉质量比为100∶10∶1的催化剂,浓硫酸用量为5.0 mL,消解时间为40 min时,1.0 g土壤样品可以消解完全,全氮含量测定值准确度最高。4种不同土壤标准物质测定结果表明,测量误差为0.01~0.03 g/kg,相对标准偏差为1.24%~4.58%(n=6),回收率为96%~98%,精密度和准确度均满足国家相关标准要求。The total nitrogen content in cultivated soil was determined by graphite digestion instrument Kjeldahl method. The effects of catalyst type, amount of concentrated sulfuric acid and digestion time on the determination of total nitrogen content were discussed. When the mass ratio of potassium sulfate, copper sulfate and selenium powder was 100/10/1,the amount of concentrated sulfuric acid was 5.0 mL, and the digestion time was 40 min, 1.0 g soil sample would be completely digested, and the accuracy of total nitrogen content determination was the most accurate. The determination results of four different soil reference materials showed that the measurement error is 0.01-0.03 g/kg, the relative standard deviation was 1.24%-4.58%(n=6), the recovery rate was 96%-98%, and the precision and accuracy met the requirements of relevant national standards.

关 键 词：土壤 全氮含量 石墨消解仪–凯氏定氮法 

分 类 号：O655.22[理学—分析化学]