基于元素分析仪测定土壤有机碳的不同前处理方法对比研究

The Comparative Study on Different Pretreatment Methods of Soil Organic Carbon Determined by Elemental Analyzer

中文关键词:  元素分析仪  土壤有机碳  银杯法  离心法  过滤法

英文关键词:Elemental analyzer  Soil organic carbon  Silver cup method  Centrifugation method  Filtration method

中文摘要:

      采用元素分析仪测定土壤标准样品中的有机碳含量,对比了银杯法、离心法和过滤法3种不同的前处理方法对测定结果的影响。以N-甲基邻苯二甲酰亚胺为加标物质,按3个不同水平加入到土壤标准样品中,开展了加标回收实验。研究结果表明,采用3种不同方法处理土壤标准物质后,其有机碳测试结果的相对标准偏差均小于9%,说明3种前处理方法均适用于土壤有机碳含量的测试。其中,离心法和过滤法的相对偏差均小于4%,其准确度和重现性优于银杯法,测试结果也更接近土壤有机碳含量真实值。离心法和过滤法的加标回收率分别为79.97%~102.09%和79.56~101.42%,明显高于银杯法的加标回收率(43.14%~69.10%)。研究结果表明,基于元素分析仪测定土壤有机碳的3种前处理方法中,过滤法最为准确和可靠。

英文摘要:

      This study compared the effects of three pretreatment approaches including silver cup method,centrifugation method,and filtration method on contents of organic carbon in standard soil samples determined by elemental analyzer.Recovery experiments were performed by adding N-Methylphthalimide to the soil samples with three addition levels.The results showed that all the RSD(relative standard deviation) values of organic carbon contents in soil standard substance determined by elemental analyzer with three pretreatment methods were lesser than 9%,indicating that these pretreatment methods could be suitable for determining the contents of soil organic carbon.The RSD values of soil organic carbon contents determined by elemental analyzer with centrifugation and filtration pretreatment methods were lesser than 4%.Compared with silver cup method,contents of soil organic carbon determined by elemental analyzer with centrifugation and filtration pretreatments were closer to the real contents.These results suggested that centrifugation and filtration pretreatment methods were better than silver cup method in accuracy and reproducibility.Recoveries of centrifuge method,filtration method,and silver cup method were in the ranges of 79.97%-102.09%,79.56%-101.42% and 43.14%-69.10%,respectively.Filtration method is the most accurate and reliable pretreatment for determining organic carbon contents in soil by elemental analyzer.