摘要
快速准确测定土壤中铵态氮、硝态氮含量对监测土壤肥力水平和生态环境,指导作物氮肥施用非常重要。选择30份土样,利用全波长扫描式多功能读数仪(酶标仪)结合靛酚蓝分光光度法、硫酸肼还原法测定土壤中铵态氮和硝态氮含量,探讨利用酶标仪测定土壤无机氮含量的可行性。结果显示,利用酶标仪测定土壤铵态氮、硝态氮含量与连续流动分析仪测定结果之间无明显差异,彼此间呈显著线性相关。铵态氮回归直线方程为Y(连续流动分析仪-NH_4^+-N)=0.997 6 X(酶标仪-NH_4^+-N)-0.012 3,相关系数R=0.961 9(n=30,P<0.01);硝态氮回归方程为Y(连续流动分析仪-NO_3^--N)=0.959 3 X(酶标仪-NO_3^--N)+0.021 9,相关系数R=0.964 0(n=30,P<0.01)。酶标仪测定铵态氮回收率在96.2%～108%,相对标准偏差在10%以内;硝态氮测定回收率为94.9%～110%,且相对标准偏差在5%以内,酶标仪测定土壤铵态氮和硝态氮方法检出限分别为0.068mg/L和0.028mg/L。酶标仪测定土壤无机氮速度快,精密度、准确度较高,消耗试剂少,可用于大批量土壤浸提液中铵态氮和硝态氮含量的快速分析。
It is important to quickly and accurately determine the ammonium and nitrate content in the soil for assessing soil fertility and ecological environment and for directing fertilizer recommendation. In this paper, the contents of NH4^+-N、NO^3--N in soil were determined through a microplate reader with indophenol-blue spectrophotometry and barium sulfate reduction method, respectively. We selected 30 soil samples for determination and compared with that of AA3 in order to establish method for soil inorganic nitrogen determination. The results of NH4^+-N and NO3^--N determined by the microplate reader and the continuous flow analyzer were compared. Regression equation for NH4^+-N was established as Y (Continuous flow analyzer- NH4^+-N)=0.997 6 X (Microplate reader-NH4^+-N)-0.012 3 with correlation coefficient R =0.961 9( n =30, P <0.01). Regression equation for NO3^--N was Y (Continuous flow analyzer-NO3^--N)=0.959 3 X (Microplate reader-NO3^--N)+0.021 9 with correlation coefficient R =0.964 0( n =30, P <0.01). The recovery rates of NH4^+-N and NO3^--N concentrations measured by the microplate reader were 96.2%- 108% and 94.9%-110%, respectively. The relative standard deviation (RSD) of proposed colorimetric method with microplate reader was less than 10% and 5%( n =6) for NH4^+-N and NO3^--N, respectively. The detection limits of NH4^+-N and NO3^--N content by the microplate reader were 0.068 mg/L and 0.028 mg/L, respectively. It is suggested that microplate reader with colorimetric method can be used for rapid analysis of ammonium and nitrate nitrogen content in soil extracts with high accuracy and precision.
作者
宋书会
王汝健
辛宇
张金尧
汪洪
SONG Shuhui;WANG Rujian;XIN Yu;ZHANG Jinyao;WANG Hong(Institute of Agriculture Resources and Regional Planning, China National Center for Quality Supervision and Test of Chemical Fertilizers(Beijing), Laboratory of Quality and Safety Risk Assessment for Agricultural Products from Fertilizer Sources, Ministry of Agriculture and Rural Affairs (Beijing),Beijing 100081,China)
出处
《中国无机分析化学》
CAS
2019年第2期35-41,共7页
Chinese Journal of Inorganic Analytical Chemistry
基金
国家重点研发计划项目(2016YFD0200108)
中央级公益性科研院所基本科研业务费专项(1610132018034
Y2018PT38和2060302-03-720-69)
关键词
铵态氮
硝态氮
酶标仪
土壤
ammonium nitrogen
nitrate nitrogen
microplate reader
soil
