2种方法测定溶解性有机碳和总氮含量比较研究  

Comparison of Two Measurement Methods of Dissolved Organic Carbon and Dissolved Total Nitrogen

作　　者：银莲 徐星凯[2] 景元书[1] 

机构地区：[1]气象灾害预报预警与评估协同创新中心,南京信息工程大学应用气象学院,江苏南京210044 [2]中国科学院大气物理研究所,大气边界层物理和大气化学国家重点实验室,北京100029

出　　处：《环境科学与技术》2015年第9期93-97,103,共6页Environmental Science & Technology

基　　金：全球变化研究国家重大科学研究计划(2010CB950602);国家自然科学基金(41175133,41275166,21228701,41321064)

摘　　要：该文采用岛津TOC-VCSH/TN分析仪与连续流动分析仪,分别运用高温催化燃烧法和湿化学氧化法测定已知质量浓度溶液、森林土壤零张力渗漏液、水浸提液和K2SO4浸提液样品中的溶解性有机碳（DOC）与溶解性总氮（DTN）含量。针对已知质量浓度DOC和DTN标准溶液,2种仪器测定结果平均值接近实际值,相对误差〈3%,相对标准偏差〈5%,显示基于上述2种方法仪器分析均具有良好的准确度和精密度。在测定不同未知样品中DTN含量时,连续流动分析仪测定结果相当于总有机碳/总氮分析仪测定结果的1.06-1.23倍（R2≥0.98）,且随着样品DTN浓度的增高此差异增大;两仪器测定土壤零张力渗漏液和土壤K2SO4浸提液DOC结果较接近,比值（总有机碳/总氮分析仪测定结果比连续流动分析仪测定结果）为0.99-1.04（R2≥0.99）,但是在测定土壤水浸提液DOC含量时,连续流动分析仪测定结果仅相当于总有机碳/总氮分析仪的0.79倍（R2≥0.99）。上述结果显示,基于高温催化燃烧法和湿化学氧化法均能有效的分析环境液体样品中DOC和DTN含量,后者更适用于大批样品的快速测定。High temperature catalytic combustion method was compared with a wet chemical oxidation method in measuring concentrations of dissolved organic carbon （DOC） and dissolved total nitrogen （DTN） in known samples, forest soil zerotension percolates and soil extracts by using Shimadzu TOC-VCSH analyzer and continuous flow analyzer（ CFA ）. The results Of both analyzers were close to actual values of DOC and DTN concentrations in known samples, with a relative error less than 3% and a relative standard deviation less than 5%. As results, both methods had a good accuracy and precision. The measurement results DTN in unknown samples by CFA was 1.06-1.23 times larger than those by TOC/TN analyzer（R^2≥0.98）, and the differences increased with increasing concentration of DTN. The differences in DOC concentrations of soil zerotension percolates and soil K2SO4 extracts were not significant according to measurements of two analyzers （0.99-1.04, the ratios for the TOC/TN analyzer to CFA, R^2≥0.99）. However, CFA analyzer gave a greater value in measuring DOC concentration in soil water extracts in comparsion with TOC/TN analyzer （0.79, the ratio for the TOC/TN analyzer to CFA, R^2 ≥0.99）. From the above results, it can be reasonably concluded that both methods have a good efficiency in measuring DOC and DTN in environmental liquid samples, and the continuous flow analyzer is more suitable for a rapid measurement of large number of samples.

关 键 词：高温催化燃烧法 湿化学氧化法 溶解性有机碳 溶解性总氮 森林土壤溶液 

分 类 号：X830.2[环境科学与工程—环境工程]