分光光度法测定石灰性土壤阳离子交换量的相关探讨

Related Discussion of Determination of Cation Exchange Capacity(CEC)in Calcareous Soil by Spectrophotometry

对分光光度法和乙酸钙交换法测定石灰性土壤阳离子交换量进行了比对,结果表明:2种方法在标准曲线线性相关性、精密度、准确度等方面均能满足阳离子交换量的分析测定和质量控制要求。分光光度法因实验操作简单,分析准确度、精密度均高于乙酸钙交换法,较大程度地提高了分析效率,更适用于大批量土壤样品的分析测试。同时,对三氯化六铵合钴浸提-分光光度法浸提实验进行了相关探讨,结果显示:实验试剂、浸提温度、振荡条件的选择均对分析准确度有着一定程度的影响。

In this paper,the determination of cation exchange capacity in calcareous soil has been compared by spectrophotometry and calcium acetate exchange method.Both methods can meet the analysis and quality control requirements in terms of linear correlation,precision and accuracy.Based on its easier experimental manipulation,higher precision and accuracy,spectrophotometry is more suitable for the analysis and testing of large quantities of soil samples compared with the calcium acetate exchange method.The experiment of extraction spectrophotometry with hexaammine cobalt(III)chloride has been discussed at the same time.The results showed that the selection of reagents,extraction temperature and oscillating conditions all affected the analytical accuracy in a certain extent.