电热消解–光能电子滴定法测定土壤中有机质  

Determination of organic matter in soil by electrothermal digestion–photoelectronic titration

作　　者：高飞 GAO Fei(Beijing Cultivated Land Construction Protection Center,Beijing 100101,China)

机构地区：[1]北京市耕地建设保护中心,北京100101

出　　处：《化学分析计量》2022年第7期39-42,共4页Chemical Analysis And Meterage

摘　　要：建立电热消解–光能电子滴定法测定土壤中有机质的检测方法。称取0.0500~0.5000 g土壤样品,置于定制的消解管中,加入10.00 mL 0.4 mol/L重铬酸钾的硫酸溶液,用电热消解仪在180℃下消解6 min,消解液冷却后,以邻菲啰啉为指示剂,使用光能电子滴定器,以0.1 mol/L硫酸亚铁标准溶液滴定剩余重铬酸钾,根据消耗的硫酸亚铁标准溶液量计算土壤中有机质的含量。耕层土壤样品5次测定结果的相对标准偏差为0.70%~1.24%;6种土壤标准样品测定值均在标准值不确定度范围内,相对误差为0.40%~2.15%。该方法测定结果与NY/T 1121.6—2006《土壤检测第6部分:土壤有机质的测定》方法的测定结果呈极显著相关。A method for the determination of organic matter in soil by electrothermal digestion–photoelectronic titration was established.0.0500–0.5000 g soil sample was weighed,put into a customized digestion tube,and added 10.00 mL of 0.4 mol/L potassium dichromate sulfuric acid solution,digested with an electrothermal digester at 180℃for 6 min.After the digestion solution was cooled,a light energy electronic titrator was used to titrate the remaining potassium dichromate with 0.1 mol/L ferrous sulfate standard solution with o-phenanthroline as indicator,and calculated the content of soil organic matter according to the consumed ferrous sulfate standard solution.The relative standard deviation of five determination results of topsoil soil samples was 0.70%–1.24%.The measured values of six soil standard samples were all within the uncertainty range of standard values,and the relative errors were 0.40%–2.15%.The results of this method are significantly correlated with those of the standard method in NY/T 1121.6–2006 Soil Testing Part 6:Determination of Soil Organic Matter.

关 键 词：电热消解 光能电子滴定 土壤有机质 

分 类 号：O656.3[理学—分析化学]