元素分析仪同时测定土壤中全氮和有机碳  

Simultaneous determination of total nitrogen and organic carbon in soil with an elemental analyzer

作　　者：王巧环[1] 任玉芬[1] 孟龄[1] 李虹[1] 傅慧敏[1] 王华锋[1] 

机构地区：[1]中国科学院生态环境研究中心,城市与区域生态国家重点实验室,北京100085

出　　处：《分析试验室》2013年第10期41-45,共5页Chinese Journal of Analysis Laboratory

基　　金：国家自然科学重点基金(41030744;41201049)项目资助

摘　　要：通过采用HCl对土壤无机碳去除效果的研究,建立了对不同酸碱性的土壤采用不同的前处理方法,达到了用元素分析仪同时测定土壤中全N和有机C的目的。结果表明,酸性土壤制备到进样要求即可直接用元素分析仪同时测定土壤全N和有机C;碱性土壤用1 mol/L HCl充分去除无机碳后可直接用元素分析仪同时测定土壤全N和有机C;测定全N的相对标准偏差在0.34%～3.8%之间,平均值1.9%,检出限为18 mg/kg;测定有机C的相对标准偏差在0.12%～5.0%之间,平均值1.4%,检出限为61 mg/kg;精密度高于传统的凯氏法和容量法。By studying the removing effect of inorganic carbon from soil,a method for soils of different pH pretreated using different methods was established,and simultaneous determination of total nitrogen（TN） and organic carbon（OC） in the soil with an elemental analyzer（EA） was achieved.The results showed that the TN and OC of acid soils could be directly measured with elemental analyzer（EA）,but the inorganic carbon should be removed completely from the alkaline soil with 1mol / L hydrochloric acid before measurement with EA.The relative standard deviations（RSD） of TN were in the range of 0.34%-3.8%,the average was 1.9%,and the detection limit was 0.018g / kg for the EA method;the RSD of OC were in the range of 0.12%-5.0%,the average was 1.4%,and the detection limit was 0.061g / kg for the EA method.The precisions of EA method for the determination of soil TN and OC were higher than those by the traditional method--Kjeldahl method and volumetric method.

关 键 词：元素分析仪 土壤 全氮 有机碳 

分 类 号：O657[理学—分析化学]